Hazards, Hazardous Substances,
the Minamata Convention on Mercury and Other Stuff
Bruce Hartley
Meteorological Service of New Zealand Limited
30 Salamanca Road, Kelburn, Wellington 6012, New Zealand
[email protected]
30 August 2016
Abstract:
This paper is a presentation on topics relating to Hazards and Hazardous substances in use by the Meteorological
community. In particular identifying those that are significant and discussing ideas on what can and should be done to
eliminate and minimise risks to people, the environment and business. Discussion on "why this is so important" – i.e. to
not only act as a good global citizen, but also to meet local legal requirements (e.g. the new Health and Safety at Work
Act, 4 April 2016 in New Zealand). The Minamata Convention on Mercury will be looked at to identify the applicable goals
and time-line of this global treaty. WMO IOM report 117 "Survey on Alternatives for Dangerous and Obsolete
Instruments" will be visited to identify highlights of what has and is being done in the global meteorological community
(circa 2015). Known solutions with pros and cons will be discussed. Finally some ideas and options currently under
investigation by various organisations will be reported on, with comments on usefulness and discovered issues.
Abbreviations
AWS
Automatic Weather Station
IMOP
Instruments and Methods of Observation Program
VOS
Voluntary Observing Ship
Introduction
How did this paper start? We have a project at MetService that that is the replacement of all mercury thermometers on
VOS - primarily to meet the requirements of the United Nations Minamata Convention. MetService has only a small
number of VOS so the project has a moderate priority because we know we can quickly deploy to all stations. While
reviewing the options for the project I was conscious that there was a flurry of activity some years ago in the
Meteorological community about the replacement of all instruments that contained mercury. I also was aware that in the
last two years there had been only minor mention of this in the literature or in the wider discussion circles. A quick search
of the major Meteorological publications that I follow revealed the following references to Minamata and Mercury:
TECO-2010
No relevant papers
TECO-2012
P1(21) A New Absolute Barometer without Mercury, Scott Kevin (Great Britain)
TECO-2014
No relevant papers
TECO-2016
Session 4(6) - AUTOMATION OF SURFACE OBSERVING NETWORK IN BMKG "BMKG’s roadmap
of surface observation network automation 2015 – 2019. It is expected that BMKG able to support the
WMO policy in eliminating the use of mercury containing instrumentation gradually before 2020".
Poster P4(8) - Challenges and plans for phasing out mercury based meteorological instruments from
Nepal "Nepal in phasing out mercury based thermometers and barometers in stipulated time of 2020".
Meteorological Technology International Publications 2012 to 2016:
Minamata:
No relevant articles or advertisements
Mercury:
August 2012 Meteormetrics - New zero-mercury absolute barometers (Company now dissolved)
August 2016 Fairmount Weather Systems - Intellisense - Replacement for mercury thermometers
August 2016 GE Measurement & Control - RPS/DPS 8100 - Replacement for mercury barometers
I am aware that many organisations are working through the process (see later in this paper), and I am also very pleased
to see two papers in addition to mine at this TECO that are directly related to this topic.
However I think it is time to again raise the topic of dis-establishment of mercury to stimulate the Meteorological
community into sharing what organisations are doing and reminding everyone why and what it is we are going to
Page 1 of 13
achieve, and to collect some of the information into one place to assist the though process and the justifications to
management for the budget and resources that will be required.
Being a "Health Safety and Wellbeing" advocate I will briefly extend the discussion in this paper beyond just mercury and
talk about being a good meteorological citizen with respect to hazardous substances we use regularly or may encounter
from time-to-time.
Health and Safety
We all live on the same planet and so we all share the environment on global, regional, local and personal scales. This is
why the weather is so important to us - because it affects us all to some extent, and it is why members of the WMO
spend so much time and effort on all things about the weather on all time scales. This same philosophy and urgency
should be employed to health and safety i.e. we are ALL to some extent responsible for the environment is which we live,
work and play, so we all have a responsibility to all humanity, our neighbours, fellow workers, family and ourselves to
ensure we are safe and healthy - to do this we all need to see and act whenever necessary.
In New Zealand a new Health and Safety at Work Act was passed into legislation on 4 April 2016. This act places a
greater legal responsibility on employers and employees to ensure all practicable steps are taken, and measures are put
in place to minimise the risk of harm. The purpose of the new legislation is to protect all against harm by making sure
everyone plays their part - to achieve the best safety outcomes - by ensuring everyone works together to manage risks.
Making sure we provide a healthy and safe environment for everyone is not only the right thing to do, it is in most cases
also a legal requirement with harsh penalties for those that do not take all the practicable steps.
In the area of meteorological measurements it is a responsibility of all of us to ensure risks of potential harm associated
with hazards are identified, and then eliminated or minimised. The first step in this process is to identify those processes
that pose significant risk of harm and discussing ideas on what can and should be done to eliminate and minimise risks
to people, the environment and business. Next the hazard should be eliminated if practicable - for example this could
mean replacing equipment that is hazardous or that contains hazardous chemicals. If elimination is not practicable then
recognised practises should be implemented that minimise the likelihood of an accident and/or that limiting the amount of
potential harm during an accident - for example this could mean implementation of approved practices when handling
Hydrogen including having: documented handling practices, appropriately safe handling environment, trained staff,
equipment inspection and certification, Personal Protective Equipment (PPE), incident registers.
From the two examples above it is clear that the effort required to have safe practices in place for handling hazardous
items generally requires far more effort than eliminating a hazard, as long as a replacement process/system can be
found.
Some Hazards Associated with Meteorological Instruments and Systems
When reviewing hazards it should always be kept in mind we are looking for things that are not only hazardous to
humans but also hazardous to the environment, and in the short term and the long term.
In the meteorological community there are some hazards that immediately come to mind that should be reviewed from
time-to-time to see if there are safer methods available. Some of these include:
û Mercury in instruments - Thermometers, Barometers; Vapor lamps e.g. Dobson instruments and calibration
lamps; Mercury limnimeters (for water-level measurement); Mercury oxide (HgO) reduction detector to detect CO;
û Hydrogen gas used to "fly" a radiosonde - Extremely explosive;
û Chemicals used for the producing of hydrogen - Using NaOH and Aluminium and water;
û Electrolyser used for the producing of hydrogen - Conatin Asbestos, NaOH & distilled water;
û Chemicals used for the cleanup of other hazardous chemicals - acetic acid used to neutralise NaOH;
û Oil baths for calibration - flash points of heated oils;
û Main powered equipment - Electrical shock;
û Paints - fumes;
û Dust - breathing, ingestion;
û Welding joints - metal protective pickling chemicals;
û Batteries - explosions, chemical burns, Ingestion (particularly children);
û There are a many more, and some are not so obvious.
For the remainder of this paper I will talk about mercury and the Minamata Convention because this is one hazard that is
being addressed on a global scale through the efforts of the United Nations (UN), and the WMO has provided guidance
all its members on the processes and time-line that is required to meet the UN objectives.
Page 2 of 13
What is the Minamata Convention on Mercury all About?
Official United Nations site:
http://www.mercuryconvention.org
United Nations Environment Programme: http://www.unep.org/chemicalsandwaste/Mercury/tabid/434/Default.aspx
Wikipedia on the Convention:
https://en.wikipedia.org/wiki/Minamata_Convention_on_Mercury
Wikipedia on the disease:
https://en.wikipedia.org/wiki/Minamata_disease
Why an international agreement on mercury?
Mercury is a highly toxic substance, which has serious effects on human health and on the environment.
It can cause harmful effects on the nervous, digestive and immune systems and may be fatal. It can also cause
neurological and behavioural disorders and symptoms such as insomnia, memory loss, neuromuscular effects,
headaches, and cognitive and motor dysfunction. The harmful effects can be transferred from a mother to her unborn
child. Infants, children and women of childbearing age are therefore particularly at risk.
The presence of mercury in the environment is a global problem as mercury can readily enter and be widely transported
through the atmosphere, oceans and the food chain. It accumulates in the food chain. Consuming food with mercury in it
is a major source of exposure to mercury for both people and some animals.
Mercury is released both through natural sources such as volcanic and geothermal activity and human activity such as
industrial processes (e.g., cement and steel manufacturing and some forms of power generation) and waste disposal
(e.g., disposal of electronic equipment containing mercury, including some batteries and lighting equipment).
Mercury occurs naturally in the earth’s crust, but human activities, such as mining and fossil fuel combustion, have led to
widespread global mercury pollution. Mercury emitted into the air eventually settles into water or onto land where it can
be washed into water. Once deposited, certain microorganisms can change it into methylmercury, a highly toxic form that
builds up in fish, shellfish and animals that eat fish. Most human exposure to mercury is from eating fish and shellfish
contaminated with methylmercury, both in the United States and worldwide.
Almost all people in the world have at least trace amounts of methylmercury in their tissues, reflecting its pervasive
presence in the environment. Some communities eat significantly more quantities of fish than the general population, and
thus may be exposed to much greater mercury contamination than the general population.
Time-Line of the Convention
Since 2008 there have been negotiations to develop an international agreement on mercury under the umbrella of the
United Nations Environment Programme (UNEP).
The Minamata Convention on Mercury is a global treaty to protect human health and the environment from the adverse
effects of mercury. It was agreed at the fifth session of the Intergovernmental Negotiating Committee on mercury in
Geneva, Switzerland 19 January 2013 and adopted later that year on 10 October 2013 at a Diplomatic Conference
(Conference of Plenipotentiaries), held in Kumamoto, Japan where many countries became Signatories.
The Convention requires countries to take appropriate measures to phase out, by 2020, the import, export and
manufacture of specific types of products that contain mercury (with exceptions and the ability to lodge exemptions), and
to discourage new mercury products without environmental or health benefits. Exemptions can apply (upon application
and approval) where there is greater health or other benefits than there are detriments e.g. dental amalgam. No
exemptions will apply after 2030.
Ratified the convention does immediately create obligations on a country. Signing the convention (being a signatory)
does not create obligations on a country until the Convention has become ratified which happens 90 days after fifty
countries have ratified it.
As of 29th August 2016 there were:
128 Signatories
29 Ratifications
What the Convention Addresses
•
The direct mining of mercury
•
Export and import of the metal
•
Mercury emissions from some industrial activities
•
Artisanal gold mining that uses mercury
•
Significant releases to land and water
•
Safe storage
<< Meteorological impacts
•
Contaminated sites and waste mercury
<< Meteorological impacts
<< Meteorological impacts
Natural emissions from sources such as geothermal activities are not part of the convention.
Page 3 of 13
WMO Objectives on Mercury
The WMO has set the goal to facilitate for the replacement of mercury containing meteorological instruments (barometer,
thermometers et.al.) from the member countries before the UNEP Minamata Convention on banning production, import
and export of mercury comes into force globally in 2020.
Seventeenth World Meteorological Congress - Geneva 25 May–12 June 2015 - Resolution 27
Minamata Convention on Mercury
4.2.2.71 Congress noted that the Minamata Convention on Mercury (http://www.mercuryconvention.org/),
developed by UNEP, is a global treaty to protect human health and the environment from the adverse effects of
mercury, which is planned to enter into force in 2020. Congress recognized that this Convention would have a
significant impact on Members still using mercury instruments and requested them to develop roadmaps to
prepare themselves to introduce alternative instruments in their network and to ensure the continuity and quality
of their observations, including carrying out parallel observations, as appropriate. Congress requested CIMO to
support Members by developing appropriate guidance material and supporting the identification of appropriate
replacement instruments. Congress urged Members having already transitioned away from mercury to publish
their findings and share their expertise on a single platform that is accessible to all Members.
Attributes Specific to the Surface-Based Sub-System of Wigos
3.3.2 Requirements on Sensors
3.3.2.1 Members shall avoid the use of mercury in their observing systems. Where mercury is still in use,
Members shall obey the safety precautions provided.
Note 1: The Guide to Meteorological Instruments and Methods of Observation (WMO-No. 8), Part I, Chapter 3
(3.2.7) provides safety precautions.
Instruments and Methods of Observation Programme - Relevant paragraphs
Considering:
(10) The need to comply with the Minamata Convention on Mercury when it enters into force in
2020 and the impact it will have on Members that are still using mercury-based instruments in their networks,
Requests Members:
(3) To share their expertise and publish reports on the operation of advanced observing
systems, as well as on the process they followed to phase out mercury from their observing systems;
Prof. B. Calpini, President Commission for Instruments and Methods of Observation
IOM 117 - Survey on Alternatives for Dangerous and Obsolete Instruments, 2015 - Foreword
Protection of the Earth’s people and property from weather and climate-related events is the core business of
WMO. Unfortunately, protection from these natural hazards has in some cases involved the introduction of
meteorological instruments containing toxic or dangerous substances, which represent man-made hazards to the
environment and to the meteorological staff who use them. The most prominent of these man-made hazards are
mercury, hydrogen and microwave emissions.
Increasingly, government regulations in many countries are being introduced which restrict the use of equipment
containing toxic substances. Indeed, the UNEP Minamata Convention on Mercury, already in force in the
European Community, is expected to come into force globally in 2020, and this will ban the manufacture, import
or export of mercury-containing instruments everywhere. Fortunately, technologies have evolved in some cases
that now enable the meteorological community to reduce the use of such dangerous substances.
Cimo Management Group, Fourteenth Session, Offenbach, Germany 5 – 8 April 2016.
Congress 17 Paragraph 4.2.2.71 was included as agenda item 17 and the "Considering: (10)" and "Requests
Members: (3)" were included in an appendix.
OPAG Capacity Building - Expert Team on Operational Metrology
The outreach flyer on impact of Minamata convention was developed and published by WMO at the Congress in
spring 2015 and is available on the IMOP web page (see following section)
Focus on the activities of the ET related to development of guidance for transition from mercury-based
instruments to alternative technologies, guidance on selection of modern instruments replacing outdated
instruments and guidance on maintaining and calibrating modern instruments. To continue developing guidelines
for Members planning the road-map for transition from mercury sensors to electronic devices before the year
2020 (the expected year in which the Minamata Convention will be in effect). To develop guidance for the choice
of modern alternatives and to define their minimum metrological specifications and their reliability in field
conditions.
Page 4 of 13
CIMO Editorial Board (CIMO Management Group, Fourteenth Session, Offenbach, Germany, 5 – 8 April 2016)
Expert Team on Operational Meteorology (ET Opmet) proposed changes related to Minamata and to do a more
in-depth review of Chapter 2 to 4.
WMO Knowledge Sources
IMOP - Home Page (see "Use of Mercury"):
http://www.wmo.int/pages/prog/www/IMOP/IMOP-home.html
and IMOP - Knowledge-sharing Portal (see "6. Safety Procedures"):
http://www.wmo.int/pages/prog/www/IMOP/Knowledge-sharing_Portal.html
o Information Flyer on Mercury-based Instruments Ban (WMO, 2015)
o UNEP Minamata Convention on Mercury http://www.mercuryconvention.org
o Mercury [Hg]: How to prevent severe illness and to protect the environment (KNMI, 2010)
The "KNMI, 2010" web site is an excellent background document - 87% of the following IOM 117 Survey respondents
(see following paragraph) agreed that the information on this web page was sufficient for them to plan and implement the
disestablishment of mercury based instruments.
WIGOS - Publications:
WIGOS Integrated Global Observing System - WIGOS Newsletter, April 2016
http://www.wmo.int/pages/prog/www/wigos/Newsletters.html
4. The Minamata Convention
Despite the accelerating transition of NMHSs toward automatic systems for surface observation, the use of conventional
instruments containing mercury is still common. The results of global and regional surveys (IMO reports N°117 and 122)
conducted by CIMO on behalf of WIGOS show that the use of these instruments remains widespread. For example, over
75% of the RA II countries surveyed use mercury barometers and thermometers. Some countries have hundreds of
mercury barometers and thermometers installed nationwide. More than 50% of the NMHSs questioned have not yet
commenced the withdrawal of mercury-based instruments even though they are aware of the danger of mercury on
health and the environment.
...
Faced with this situation, it is imperative that global awareness is ensured in order to unify and harmonize efforts to
eliminate the use of mercury-containing instruments, and to find reliable and cost-effective alternatives. It is now critically
important for the global meteorological community to commence their transition to the use of modern instruments
respectful of human health and of the environment. WMO has been contributing to the awareness of the meteorological
community by providing technical guidance (Guide to Meteorological Instruments and Methods of Observation, WMONo. 8 - Provisional 2014 Edition) and by updating reference and regulatory materials. These should be used by Members
to guide them in the development of plans for their urgent transition towards the use of alternative technologies in their
observing systems. WIGOS provides an ideal framework for addressing this issue, by promoting close collaboration
between CIMO and HMEI in the development of technically acceptable alternatives, and in disseminating advice to WMO
Members, with whom primary responsibility lies for the elimination of mercury-containing instrumentation. The WMO
RAs, too, have a key role to play in this, since they coordinate the design and implementation of observing networks
across the regions.
IMOP - Publications: http://www.wmo.int/pages/prog/www/IMOP/publications-IOM-series.html
IOM 122 - Survey on meteorological instruments, calibration and training (RA II - Asia). Nakashima 2015.
NOTE: The questionnaire did not identify if the liquid-in-glass thermometers were all mercury based or other liquid
type, however in the context of calibration it is likely that most, if not all of these thermometers are mercury based.
Questionnaire circulation 2012. Report publication 2015.
A total of 24 (approx. 70%) of all National Meteorological and Hydrological Services (NMHSs) in the region
responded.
Pressure: Mercury barometers were used by 19 out of 24 Members (79%).
Temperature: Liquid-in-glass thermometers were used by 18 out of 24 Members (75%).
Page 5 of 13
Conclusions: (5) Conventional instruments such as mercury barometers and liquid-in-glass thermometers were
still more widely used than electrical instruments for most meteorological parameters.
IOM 117 - Survey on Alternatives for Dangerous and Obsolete Instruments. Bakthavathsalu and Merrouchi, 2015.
Questionnaire circulation 2013. Report publication 2015.
There were 54 questionnaire responses from 52 countries (of 191 Members of WMO as on April 2013 i.e. 27%).
4
countries had already completely withdrawn mercury-based equipment
21
countries had commenced withdrawal
12
countries had not yet started the process but had a plan
17
countries had not yet started the process and did not yet have a plan
Primary instruments identified that use mercury and should be replaced: Mercury barometers, thermometers and
limnimeters (for water-level measurement).
64% of respondents indicated it will take greater than 3 years to procure and replace the mercury equipment with
digital ones. 56% of respondents required existing instruments be operated in parallel with new ones to establish
climatology record continuity. These figures in conjunction with noting that over half of the respondents had not
yet started the process provides some cause for concern that the 2020 year for complete dis-establishment of
mercury based instruments will likely not be met by a large number of WMO countries i.e. extrapolating from the
number of respondents to the full number of WMO members provided an indicative number of 60 countries that
will likely not have all mercury based instruments dis-established.
So if you have not already started a mercury dis-establishment plan, then the time to act is NOW.
Guide to Meteorological Instruments and Methods of Observation, WMO-No. 8, 2008 edition Updated in 2010.
There is a good section in the CIMO Guide on the hazards associated with the operation of mercury based thermometers
and barometers - see below for the topics covered. The greatest detail is contained in the chapter on barometers,
primarily because mercury is used in relatively large quantities in barometers compared to thermometers.
However the CIMO Guide is not a good resource for the process of transitioning from mercury based instruments to
other safer technologies. The only mention on transitioning away from mercury is "There is an increasing move away
from the use of mercury barometers because mercury vapour is highly toxic; free mercury is corrosive to the aluminium
alloys used in air frames (for these reasons there are regulations proscribing the handling or carriage of mercury
barometers in some countries)"
http://www.wmo.int/pages/prog/www/IMOP/CIMO-Guide.html
2.2 LIQUID-IN-GLASS THERMOMETERS
2.2.8 Safety
o Mercury is poisonous if swallowed or if its vapor is inhaled
o Reference to 3.2.7 Safety precautions for the use of mercury.
3.2 MERCURY BAROMETERS
3.2.7 Safety precautions for the use of mercury
o Containment, floor coverings, chemical co-location, ventilation, storage , regular testing of staff.
3.2.7.1 Spillages and disposal
3.2.7.2 Fire
3.2.7.3 Transportation
Page 6 of 13
Planning and Transitioning
When planning the dis-establishment of instruments and systems containing mercury, as a good global citizen you
should take the opportunity to identify other hazardous chemicals and materials that you use, and decide if it would be
appropriate to plan transitioning away from these as well.
Steps that should be considered in the process to transitioning should include at lease the following...
Planning and project management.
Identify the instruments and systems to be considered for replacement: Field measurements instruments; Travelling
standard instruments; Calibration laboratory instruments and systems; Support equipment for all the above, including
tools and office facilities.
Identify proposed replacement instruments and systems.
Evaluate the performance of proposed replacement instruments and systems compared to the existing ones, and
against general requirements i.e. will the proposed replacements perform adequately considering: Performance
specifications; Stability; Metadata requirements; Mechanical robustness for handling, transport, operating environment
(vibration, heat/cold, humidity, creatures and critters, gases, moisture, ultraviolet light, sand/dust, ice/snow/hail, etc. ).
Spares pool requirements based on Mean Time Between Failure (MTBF).
Calibration facilities and change in intervals and resources required - The need to check frequently the calibration of
electronic barometers imposes an additional burden on National Meteorological Services, particularly on those with
extensive barometer networks. The ongoing cost of calibration must be taken into consideration when planning to
replace mercury barometers with electronic barometers.
Training to achieve required expertise and competency for operation, maintenance, calibration, interpretation of data.
Budgeting - Capital costs for implementation and spares. Operating costs including: Field maintenance equipment and
labour; Calibration facilities and labour; Life cycle (time to replace), Spares pool replenishment.
Purchasing to support the roll-out and operation of the new instruments and systems.
Documentation for setup, roll-out, operation, calibration and record keeping and database upgrades required.
Handling, transport, storage, security, insurance.
Roll-out of new instruments and systems.
Climatology record continuity checks where appropriate i.e. the overlap of systems at sites to determine systematic
differences in operation - Reference: TECO 2016, Session 4(6) - Moving on from mercury: maintaining homogeneity in
meteorological records
Removal of the dis-established mercury containing instruments and systems.
Disposal of the dis-established equipment in a safe, approved and appropriate manner.
Completion including project review, reporting.
The Experiences of Nepal
Poster P4(8) "Challenges and plans for phasing out mercury based meteorological instruments from Nepal".
The above poster is on display at this conference and I encourage readers yet to start the process of transitioning away
from instruments containing mercury to view the poster or read the paper in the conference proceedings as this may
assist you. From this paper I would like to highlight some text in the abstract because it is very relevant.
The complete transformation from manual to automatic weather station and sustainability is mainly challenging in those
countries due to poor technical and financial resources since automatic system initial and operation cost are high and
also demands frequent onsite and server maintenance from qualified IT personnel. Like in other developing countries,
Nepal’s meteorological observation is mostly relying on manual observation having mercury based instruments in most of
the stations. In this context, this paper discusses the challenges and plans of Department of Hydrology and
Meteorology, Nepal in phasing out mercury based thermometers and barometers in stipulated time of 2020. The main
identified challenges to achieve this target are limited human resources, specially IT personnel in traditional based
organogram of department and financial resources. Without addressing these two major issues sustainability of recently
started automatic weather station network (AWS) is difficult. Thus, Without the adequate manpower in IT and Instrument
Section, the operation and maintenance of the newly established AWS's are impossible which will inhibit the continuous
and uninterrupted near/ real time data and put the quality of the data in questionable. Therefore, in a developing country
like Nepal, manual observation should also be given continuity with replacement of mercury based instruments with the
digital thermometers and barometers where observers can see and note down the reading from these instruments. For
this, uniform type of digital instruments are planned to be deployed in all manual networks and local observers will also
be trained well before to handle and maintain the new instruments. This approach, on one hand will phase out mercury
based instruments and on the other hand will give continuity for a homogenized manual historical data for climate studies
Page 7 of 13
Identifying Proposed Replacement Instruments and Systems
Because the performance requirements and budget circumstances vary widely across the Meteorological community it is
very much a case of "No one solution will meet everyone’s needs". It will also likely that within each Meteorological
organisation more than one solution may be required i.e. there may be different solutions within the same organisation
for ship, aviation, climatological and calibration applications.
For those yet to start dis-establishing instruments and systems containing mercury - You should talk to others in the
Meteorological community that have similar circumstances as yourselves i.e. similar in similar technology, resourcing and
instrument performance requirement, to see about what ideas they have and what they are planning/doing/have done.
Also talk to suppliers and explain your requirements to see what options they can offer.
There are many alternative methods of measuring air temperature (dry and wet bulb) and atmospheric pressure,
including small AWS, electrical digital transmitters (portable hand held or fixed) and sensors not requiring electric power
e.g. spirit based thermometers. Small AWS at reasonable prices may simply provide measurement of temperature,
humidity and pressure. The cost factor of such a small AWS, their reliability, accuracy and availability of spare-parts
needs to be ascertained before adopting them.
One source for identifying types alternatives is the CIMO Guide to Meteorological Instruments and Methods of
Observation, WMO-No. 8, 2008 edition Updated in 2010 (http://www.wmo.int/pages/prog/www/IMOP/CIMO-Guide.html).
CHAPTER 2 - MEASUREMENT OF TEMPERATURE
CHAPTER 3 - MEASUREMENT OF ATMOSPHERIC PRESSURE
When deciding on appropriate alternatives the same level of performance and traceability of instruments, both
operational and as standards, needs to be implemented.
The next section included here will present some typical commercial solutions that represent the types of solutions that
are applicable.
From IOM 117 - Survey on Alternatives for Dangerous and Obsolete Instruments (paraphrased)
Measurement of atmospheric pressure:
As an alternative of the mercury barometers, aneroid barometers and
barographs, it is possible to use digital barometers with one, two or three internal and independent sensors and if needed
with LCD screen for direct display of the barometric pressure. The benefit of the digital barometer is that data are directly
read and also archived in the internal memory of the instrument. There is no need to add corrections for gravity and
temperature changes. In addition, human errors are minimised. Digital barometers are most suitable for use as travelling
standards. Some instruments can provide derived parameters such as QNH, QFE and tendency etc.
Measurement of air temperature and relative humidity: Digital instruments taking measurements from an integrated
temperature/humidity sensor is an appropriate alternative for mercury based instruments. A digital system may be
operated from a fixed power supply or from batteries, and instruments may include an LCD display. An instrument may
include data logging to internal memory with data transfer to a laptop with the minimum and maximum temperature of the
day being extracted from the daily record. Or an instrument may be a simple unit with a screen for real time data display.
Measurement of soil temperature: As a replacement of the traditional mercury thermometers used for the
measurement of soil temperatures, a dedicated data logger can be used for the acquisition and the processing of data
coming from multiple soil temperature sensors a combined probe measuring several soil temperatures. The data is
recorded by the data logger and accessible via laptop or may be displayed on screen for direct reading.
Page 8 of 13
14628 Zeal Catalogue Update
6/3/07
5:29 pm
Page 10
Examples of Commercial Solutions for Mercury-in-Glass Thermometers
H Y G R O M E T E R S / M A X / M I N
H E Rof
M options
O M E T E Rthat
S / D are
I P P Iavailable.
N G
Here are typical examples (not recommendations or endorsements) and not a completeT list
MASONS PATTERN HYGROMETER
Housed in a yellow plastic case with lid and bulb protection.
Available in Mercury or Red Spirit.
Supplied with Hygrometric tables, spare wick and full instructions.
Portable or FIxed Spirit in Glass Thermometers
ORDER CODE
P2500
P2501
P2503
P2505
P2506
http://jayscientific.com/products/zeal-pdf/zealcatalog.pdf
Zeal spirit thermometer, ZEALP2505,
Masons - 5/50 Red Spirit, NZ$50 each
DESCRIPTION
Mercury: -5/+50°C
Mercury: -5/+50°C and 20/120°F
Wick: Pack of 10 3.5“ long
Red Spirit: -5/+50°C+°F
Red Spirit High Range: -5/+100°C
Hygrometer
WHIRLING PATTERN HYGROMETERS
Made in accordance with BS2842 this product is available in either Mercury
or Red Spirit. Supplied with folding handle, conversion tables and wick.
Note the limitations on the performance spirit in glass
thermometers - CIMO Guide 2.2.4.5 Errors
associated with spirit thermometers.
P2501
P2520
ORDER CODE
P2520
P2522
P2528
P2521
P2523
P2529/ZEAL
P2524
P2525
P2525A
DESCRIPTION
Mercury - Complete Unit: -5/+50°C
Mercury - Complete Unit: 0/120°F
Red Spirit - Complete Unit: -5/+50°C
Mercury - Spare Thermometer: -5/+50°C
Mercury - Spare Thermometer: 0/120°F
Red Spirit - Spare Thermometer: -5/+50°C
CARRYING CASE ONLY
PACK OF 25 X 3.5" WICKS 5
PACK OF 10 X 3.5" WICKS
Portable Electronic Hand Held Instruments
Rotronic HygroPalm 21/22
(left)
Vaisala HM4X series
(middle)
Vaisala HM70 series
(right)
MAX/MIN THERMOMETER
Housed in a plastic case with lid and instructions for use.
Push button re-set of indices.
ORDER CODE
P3003
P3004
PLASTIC CASED POOL & BATH THERMOMETERS
Non toxic, spirit filled tube, on a S/S scale mounted in a green plastic sampling case
All battery operated. Require exposure to the
environment to be measured until probe equilibrium is
reached.
ORDER CODE
P1506
P1510
P3004
P1510
10
Fixed Installation Electronic Instruments
Fairmount Weather Systems Ltd.
Stand alone electrical thermometers for Dry and Wet
bulb air temperatures. Shown here being operated
alongside mercury in glass thermometers for
comparison purposes.
Fixed Installation Electronic Instruments
Vaisala HMT140
(left)
Runs from rechargeable batteries that last ~18
months. Momentary reading of Air temperature and
Relative humidity. Not backlit. The probe stores the
calibration data.
Vaisala HMT3xx series
DESCRIPTION
Mercury: -40 TO +50°C
Mercury: -40 TO+50°C & -20 TO +120°F
(right)
Various probe options and optional built in display for
AWS or stand alone operation.
Portable or FIxed Electronic Instruments
Vaisala HMT155
Stand alone Relative humidity and Air temperature
probe that has built in algorithms for Dewpoint and
Wetbulb.
Requires AWS, logger or display.
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DESCRIPTION
DIPPING -30/+50°C & -20/+120°F
POOL/BATH -30/+50°C & -20/+120°F+ CABLE
MetService NZ Options for VOS Mercury Thermometer Replacement
MetService currently Mercury-in-Glass thermometers for its VOS operations. MetService has processes in place to
ensure the handling of the thermometers during normal operation, and in the event of a breakage and release of mercury
into the environment, is performed according to recognised safe practices.
To meet the obligations under the Minamata Convention MetService is planning to dis-establish the VOS Mercury-inGlass thermometers. MetService has already dis-established all land based Mercury-in-Glass thermometers and
mercury based barometers.
For its VOS operations MetService does not have a requirement for maximum or minimum temperatures observations
therefore the proposed MetService solutions are for in-situ spot measurements and are not applicable for climatological
observations. Due to the transitory nature of VOS operations a rapidly deployed/recovered system is preferred. Two
solutions have been identified as likely solutions.
Option 1:
Low cost spirit based thermometers
The use of spirit based thermometers has been employed by others (see below - Experiences in the Meteorological
Community). Their deployment is very low cost and simple in construction - A screen containing the thermometers meaning the footprint is the same as for existing Mercury-in-Glass systems.
However there are limitations with their operation - The CIMO Guide to Meteorological Instruments and Methods of
Observation, WMO-No. 8, 2008 edition Updated in 2010 has a useful section on the performance of spirit based
thermometers that should be used when considering mercury based thermometer replacement. In particular the following
is very relevant:
2.2.4.5 Errors associated with spirit thermometers
The expansion coefficients of the liquids used in spirit thermometers are very much larger than those of mercury,
and their freezing points are much lower (ethyl alcohol freezes at –115°C). Spirit is used in minimum
thermometers because it is colourless and because its larger expansion coefficient enables a larger bore to be
used. Spirit thermometers are less accurate than mercury thermometers of similar cost and quality. In addition to
having the general dis- advantages of liquid-in-glass thermometers, spirit thermometers have some peculiarities
to themselves:
(a) Adhesion of the spirit to the glass: Unlike mercury, organic liquids generally wet the glass. Therefore, when
the temperature falls rapidly, a certain amount of the liquid may remain on the walls of the bore, causing the
thermometer to read low. The liquid gradually drains down the bore if the thermometer is suspended vertically;
(b) Breaking of the liquid column: Drops of the liquid often form in the upper part of the thermometer stem by a
process of evaporation and condensation. These can be reunited with the main column, but errors may be caused
at the beginning of the process before it is noticed. The column is also often broken during transport. This error is
reduced during manufacture by sealing off the thermometer at its lowest temperature so that it contains the
maximum amount of air in the stem;
(c) Slow changes in the liquid: The organic liquids used tend to polymerize with age and expo- sure to light, with
a consequent gradual diminution in liquid volume. This effect is speeded up by the presence of impurities; in
particular, the presence of acetone in ethyl alcohol has been shown to be very deleterious. Great care has
therefore to be taken over the preparation of the liquid for the thermometers. This effect may also be increased if
dyes are used to colour the liquid to make it more visible.
The reduction of errors caused by breakage in the liquid column and the general care of spirit thermometers are
dealt with later in this chapter.
Therefore MetService will consider the use of spirit based thermometers a backup plan in case a suitable electronic
system can not be found or developed.
Option 2: Electronic stand alone system built using off-the-shelf modules
MetService is developing a simple system that comprises:
ü An HMP155 Air Temperature and Relative Humidity probe installed in a small screen (Ship or beehive style);
ü The HMP155 is programmed so that on power up it will make observations and then provide a pre-formatted
message via its serial port;
ü A small instrument cabinet appropriately located below the screen but still easily accessible by an observer;
ü In the cabinet is a battery, a small circuit board, and a low power LCD display with backlight that is viewable
through the cabinet clear lid;
ü On the side of the cabinet is an environmentally secure momentary push button switch;
When the push button is pressed the circuit will energise the HMP155 and the display for 30 seconds allowing ample
time for the observations to be recorded. The 30 second operation of the system ensures hat the battery will last long
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enough so that it can be exchanged what the same time that the sensor is replaced for its annual calibration. If required a
nominal battery top-up can be provided by a small solar panel installed on the top of the cabinet.
The estimated build cost for the cabinet, display, control circuit and battery is less than NZ$ 500. This excludes one off
project costs of prototyping, development and documentation. This price also excludes the HMP155 sensor and beehive
style screen.
The reason for selecting the HMP155 sensor for this project is because MetService already uses this sensor extensively
through it’s land based networks and therefore already has a performance record for the sensor (including on a ship),
calibration processes in place, and has ordering and setup documentation in place.
Chapter 3 _______________________________________________________________ Installation
Installation in Stevenson Screen
Possible HMP155 screen implementations.
Note that a heated HMP155 is shown in the left
screen (with flying air temperature probe).
For battery operation a non-heated HMP155 would
be implemented.
0805-008
Figure 6
LCD Display Example – Crystalfontz, CFA634-TFHKS 20x4 RS-232 Serial Character LCD.
HMP155 with T-Probe Installed in Stevenson Screen
20 x 4 LCD character screen.
High contrast back-lit screen (colour options).
Power consumption (black characters on white) at 5
volts dc: 34mA backlight off,145mA backlight on.
https://www.crystalfontz.com/product/cfa634tfhksVAISALA _______________________________________________________________________ 19
character-module-20x4-rs232-lcd#datasheets
An HMP155 sensor with a configuration string as follows will produce the display below…
Form #r#n“ RHum(%)”7.1RH #r#n“ AirT(C)”T #r#n “ Dewp(C)”TD #r#n “ WetB(C)”TW
RHum(%)
AirT(C)
Dewp(C)
WetB(C)
98.7
10.3
-1.2
4.1
Transition Experiences in the VOS Community
The following are excerpts form informal communications in the VOS community and demonstrate clearly that different
solutions apply to different organisations and applications. None of the following text should be read as final solutions
because in most cases evaluations of new systems are ongoing.
The authors of the following transcripts have all agreed that they can be approached should the reader wish to ask
questions regarding mercury replacements solutions related to VOS.
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Meteorological Service of Canada (MSC)
Chris Marshall ([email protected]), Manager Surface Weather and Climate Networks
June 2016: MSC no longer uses Hg thermometers for Temp or RH measurements from our VOS fleet, as the network
has been rationalized (many fewer ships reporting) and automated (higher frequency of observations, and generally
higher quality). Our AVOS uses pretty standard electronic sensors for both temperature (YSI thermistor) and RH
(Rotronic or Vaisala RH probe). In each case we complete a complete inspection, and verification of sensor performance
annually, with repair (if possible and cost effective), or sensor suppression between annual ship visits.
June 2016: The Hg in glass issue is however still looming for our land based cooperative climate network (CCN). We
currently have about 500 locations (was formerly as high as 1500+ stations), where volunteers report daily max/min
temperature, rainfall, snowfall, and snow on the ground. We equip each observer with a Stevenson screen (full sized), 2
liquid in glass thermometers (and usually a spare), a rain gauge, and a snow ruler. The Hg thermometer is required for
the max/min (has a floater in the glass column). We therefore have several hundred Hg thermometers in the field. In
recent years it has been getting harder to procure, and costs are rising (over $400 CDN/unit). Note that the MSC
automated surface weather and climate network (~600 stations) does not use liquid in glass, with standard using triple
configuration ventilated and aspirated thermistors (where we have power). The aviation weather networks in Canada
have also moved to digital thermometers.
June 2016: Some alternatives to replace the temperature measurements for the manual climate network. The
replacement has to be simple to use, low cost, battery powered, and not require frequent calibration. Campbell Scientific
Canada has developed a prototype unit - temperature only, that includes a LCD display. They have also done some
independent testing compared to one of our climate stations in Western Canada, and the results look good.
July 2016: EC is likely going to be preparing an Technical RFP in the coming months to prepare for Hg thermometer
replacement for our Cooperative Climate Network, perhaps the same specification could be useful for a manual VOS
application (with option to integrate RH and perhaps other parameters). We will of course be pushing for some sort of
field trial, and a number of months (2-years if we can make it) to validate data for climate users. My main concern would
performance at the extremes (cold and heat), especially with on-board battery and LED display.
Deutscher Wetterdienst, Germany - March 2016
Henry Kleta ([email protected]), Marine Network Manager
March 2016: Tested 8 different sensor models and have now moved towards handhelds (Rotronic HP22-A-DWD).
July 2016: Trialling the Handheld Rotronic Hygropalm HP22-A-DWD. After getting the first ones back from the ships for
recalibration, and the majority of the handhelds (the measuring cell itself) is beyond the possibility to calibrate or repair,
they are mostly damaged due to corrosion or mechanical issues (broken wire etc.). We are still investigating, so please
don't take this as an official report. The HP22 needs more than 15min to get the sensor measurement from the bridge
temp to outside temp.
National Weather Service USA
Paula Rychtar ([email protected]), OS Program - Deputy Program Manager/Operations, NOAA
March 2016: The US found a great product of marine grade instrument shelters from a company in the UK, MetSpec
Ltd. We purchased quite a few back in 2013 and we have not had to replenish as of yet. We bought the MET 14
shipboard instrument shelters and the ZEAL hygrometers fit nicely, but you need to insure that your wet/dry bulb set
would fit in this unit…if not you may need to go with different dimensions. MetSpec can work with you on that if you so
chose to go to that company. When we purchased them, they were 172.60 per unit, and for the quality and marine grade
we wanted, I feel that was a good price for that product. They are quite nice looking as far as instrument shelters go!
June 2016: The U.S. has been removing mercury thermometers for quite some time. When I first came on-board in 2004
there was already a push to do so and since that time, VOS has not purchased anymore mercury products whatsoever
and have replaced all of the dry/wet bulbs in shelters with the Zeal, which is alcohol. To date, we are mercury free.
June 2016: So, all I can say about this is, before all of the mercury was replaced by Zeal, there should have been a
requirement to do a comparison on them to see how the Zeal compared to the mercury…so we could insure quality and
continuity was insured. This was not done I am afraid. I have asked the PMO’s to do so for the few digitals that we
have…before they are common place in the field. I want to insure that we record each new instrument along side the
old…so we can produce some type of analysis for metadata purposes…climatology…. continuity.
July 2016: We are also planning to purchase the Extech Temp/Humidity meter handheld RH300, which runs around
$80. This will be for the remainder of the fleet, other than any ships that are determined to need intrinsically safe
instruments, which I have not finalized at this time. Until then, I believe sticking with the Zeal until we can properly and
unmistakably make a decision on that.
July 2016: Currently the US has purchased PHT771 Psychrometer /hand held and the cost was around $185. These
were identified as the instruments that would be placed on ships considered as VOSClim. The specs are here
http://www.prostatcorp.com/psychrometer.
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UK Meteorological Office
Sarah North ([email protected]), Ship Observations Manager, Met Office, United Kingdom
June 2014: First we tried the Testo 625 with a remote sensor that we put in the marine screen. I like this approach but
unfortunately the system failed. We then tried a Vaisala HM34 which also failed (perhaps because we were trying to
keep the device in the screen outside – to avoid having to wait ten minutes for the system to settle down). Lastly we tried
the Rotronic Hygropalm (in this case we ask the officers to put it in the marine screen for five to ten minutes before going
out to take a reading. The rest of time it is kept on the bridge). This system is still working.
Sept 2014: We were thinking of moving over to organic spirit thermometers but the ones we trialled were expensive and
the result were rather mixed and failed to confirm that the quality accorded with the same British Standards
Nov 2015: As a stop gap we have purchased a handful of Rotronic HygroPalm hand held devices e.g.
http://www.ima.co.uk/products/by-manufacturer/rh-measurement-rotronic/hygropalm22-a
for the ships that aren’t
subject to intrinsic safety requirements.
March 2016: MetSpec screens tend to be more robust as they are metal moulded and coated plastic, whereas the Aztec
screens are mostly plastic moulded but with steel supporting bolts and fixings. For the UK VOS we will initially stick with
the Aztec screens, but bear in mind that both screens are designed around mercury in glass thermometers.
April 2016: Vibration is a major problem on most large ocean going ships, and is exacerbated now that we raise them
above the handrail level to reduce parallax. We have recently introduced more robust steel stanchions which will help a
bit but I suspect its always going to be a bit of an issue.
Other
The French are already fully automatic for VOS operations (unconfirmed third party information).
The Dutch have implemented spirit based thermometers for VOS operations (unconfirmed third party information).
Summary
If you have instruments or systems in you network that contain mercury, including support systems like calibration
laboratories or field test instrument, and you have not yet started dis-establishing these, then the time to start is NOW.
There is no “one-size-fits-all” solution. Potential solutions include full AWS, small AWS, fixed electronic instruments (with
or without displays), portable handheld instruments (with or without displays), mechanical instruments with indicators e.g.
spirit-in-glass thermometers.
Search the Internet and talk to others in the meteorological community to discuss potential solutions and issues that have
already been encountered. Ask CIMO for direction and guidance.
The transition process involves a significant amount of work and organisation – It is recommended that a project
manager is appointed to oversee the process and ensure ALL steps are correctly followed and implemented (see
Planning and Transitioning above).
Remember to perform a side-by-side comparison between the new system and the system being dis-established. The
climatologists will appreciate this.
All dis-established equipment containing mercury MUST be transported, stored and eventually disposed of in an
environmentally responsible way. Approach you government to determine how this should be performed. Do NOT put
anything containing mercury in the trash.
Lets all make the world a safer and healthier place – because I live in it and so do you.
Notes
The designations employed in this publication and the presentation of material in this publication do not imply the
expression of any opinion whatsoever on the part of the author or the WMO concerning the legal status of any country,
territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries.
The mention of specific companies or products does not imply that they are endorsed or recommended by the author in
preference to others of a similar nature which are not mentioned or advertised.
The findings, interpretations and conclusions expressed by author are those of the author alone and do not necessarily
reflect those of any articles or publications, or other parties referenced in this paper.
End
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