Matakuliah
Tahun
Versi
: H0262 / Pengukuran dan Instrumentasi
: 2005
: 00 / 01
Pertemuan 10
Sistem pengukuran panas
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Mahasiswa dapat menjelaskan sistem
pengukuran panas
2
Outline Materi
• Materi 1 : Pendahuluan
• Materi 2 : Sistem Pengukuran radiasi
panas
• Materi 3 : Detector dan elemen signal
conditioning
• Materi 4 : Sistem Pyrometer
• Materi 5 : Infra red Gas Analyzer
3
Sistem Pengukuran Panas
1. Pendahuluan
Mekanisme conduction
convection
radiation
W = U A ( T – TF )
Dimana U =koefisien heat transfer : Wm-2 0C -1
NU =  ( Re , Pr )
dimana Nusselt
Nu = Ud / k
Reynolds Re = d / 
Prandtl
Pr = c / k
d = sensor diameter
 = fluid velocity
 = fluid density
 = fluid viscosity
c = fluid heat capacity
k = fluid thermal conductivity
5
•Sistem pengukuran radiasi panas
Gb 10.1 Thermal radiation measurement system
6
Total power by black body Stefan`s law :

VTOT =
C1 d 
0 5 [ exp (C2/T ) – 1 ]
=  T4 W cm -2
dimana  = 5.67 x.10-12 W cm –2 0 K-4
konstanta Stefan - Boltzman
7
Gb 10.2 Power spectral density by black body radiation
8
•Detector dan elemen signal conditioning
Karaktersitik performance detector :
sensitivity KD
time constant
wavelength response
Noise Equivqlent Power ( NEP)
( S/N ) ( A  f )0.5
D* =
p
cm Hz0.5W-1
9
Gb 10.3 various detector
10
•Pyrometer system
two colour pyrometer system :
R (T) =
2
(
1
) 5 exp
C2
T
1
(
2
-
1
1
)
11
Gb 10.4 sistem pengukuran temperatur radiation
12
•Infra Red Gas Analyzer
T (  ) untuk acetylene ( C2 H2 ) dan CO
A( ) =1 -T( )
More power at 5 m will reach detector from the.
sample cell than from the reference cell.
The amount energy at 5 m absorbed by each
section will be different .
13
Gb 10.5 non dispersive IR analyzer dan karakteristik transmisi.
14
<< CLOSING>>
15