Pyrometers are commonly used for high temperature measurement, but their accuracy is often limited by uncertainty in the surface emissivity. Radiation heating introduces additional errors due to the extra light reflected off the measured surface. While many types of specialized equipment have been developed for these measurements, this work presents a method for measuring high temperatures using single color pyrometers when the surface emissivity is unknown. It is particularly useful for correcting errors due to reflected light in solar heating applications. The method requires two pyrometers and is most helpful for improving measurement accuracy of low cost commercial instruments. The temperature measurements of two pyrometers operating at different wavelengths are analyzed across a range of sample temperatures to find the surface emissivity values at each wavelength that minimize the difference in temperature measurements between pyrometers. These are taken as the surface emissivity values, and the initial temperature measurements are corrected using the calculated emissivity values to obtain improved estimates of the surface temperature. When applied to temperature data from a solar furnace, the method significantly decreased the difference in the temperature measurements of two single color pyrometers. Simulated temperature data with both random noise and systematic errors are used to demonstrate that the method successfully converges to surface emissivity values and reduces temperature measurement errors even when subjected to significant errors in the model inputs. This method provides a potential low cost solution for pyrometric temperature measurement of solar-heated objects. It is also useful for temperature measurement of objects with unknown emissivity.

1.
Salikhov
,
T. P.
, and
Kan
,
V. V.
, 2003, “
Advanced Multiwavelength Pyroreflectometry for Measuring True Temperature on Solar and Imaging Furnaces and Under Laser Effect
,”
Appl. Solar Energy
,
39
(
1
), pp.
66
76
.
2.
Guesdon
,
C.
,
Alxneit
,
I.
, and
Tschudi
,
H. R.
, 2006, “
1 kW Imaging Furnace With In Situ Measurement of Surface Temperature
,”
Proceedings of the 11th International Conference on Ion Sources
, AIP, Caen, France, Vol.
77
, pp.
35102
35103
.
3.
Tschudi
,
H. R.
, and
Schubnell
,
M.
, 1999, “
Measuring Temperatures in the Presence of External Radiation by Flash Assisted Multiwavelength Pyrometry
,”
Rev. Sci. Instrum.
0034-6748,
70
(
6
), pp.
2719
2727
.
4.
Salikhov
,
T. P.
,
Kan
,
V. V.
, and
Riskiev
,
T. T.
, 2001, “
Problems of Temperature Measurement in Solar Furnaces
,”
Appl. Solar Energy
,
37
(
2
), pp.
58
64
.
5.
Rohner
,
N.
, and
Neumann
,
A.
, 2003, “
Measurement of High Temperatures in the DLR Solar Furnace by UV-B Detection
,”
ASME J. Sol. Energy Eng.
0199-6231,
125
(
2
), pp.
152
160
.
6.
Zabor
,
R. S.
,
Lewis
,
W. S.
, and
Mackie
,
P.
, 1984, “
In Situ Emissivity Measurements With a Four-Wavelength Pyrometer
,”
Proceedings of the 22nd National Heat Transfer Conference
, AIChE, Niagara Falls, NY, pp.
321
325
.
7.
Nordine
,
P. C.
, 1986, “
The Accuracy of Multicolor Pyrometery
,”
High. Temp. Sci.
0018-1536,
21
, pp.
97
109
.
8.
Coates
,
P. B.
, 1981, “
Multi-Wavelength Pyrometry
,”
Metrologia
0026-1394,
17
, pp.
103
109
.
9.
Hernandez
,
D.
,
Olalde
,
G.
, and
Gineste
,
J. M.
, 2004, “
Analysis and Experimental Results of Solar-Blind Temperature Measurements in Solar Furnaces
,”
ASME J. Sol. Energy Eng.
0199-6231,
126
(
1
), pp.
645
653
.
10.
Pfander
,
M.
,
Lupfert
,
E.
, and
Heller
,
P.
, 2006, “
Pyrometric Temperature Measurements on Solar Thermal High Temperature Receivers
,”
ASME J. Sol. Energy Eng.
0199-6231,
128
(
3
), pp.
285
292
.
11.
Pfander
,
M.
,
Lupfert
,
E.
, and
Pistor
,
P.
, 2007, “
Infrared Temperature Measurements on Solar Trough Absorber Tubes
,”
Sol. Energy
0038-092X,
81
(
5
), pp.
629
635
.
12.
Beninga
,
K. J.
,
Davenport
,
R. L.
, and
Johansson
,
S. N.
, 1995, “
Design, Testing, and Commercialization Plans for the SAIC/STM 20 kWe Solar Dish/Stirling System
,”
Proceedings of the 30th Intersociety Energy Conversion Engineering Conference
, ASME, Orlando, FL, Vol.
2
, pp.
487
489
.
13.
Jacobson
,
B.
,
Gleckman
,
P.
, and
Holman
,
R.
, 1991, “
Very High Temperature Fiber Processing and Testing Through the Use of Ultra-High Solar Energy Concentration
,”
Proceedings of the ASME-JSES-JSME International Solar Energy Conference
, pp. 319–324.
14.
Kongtragool
,
B.
, and
Wongwises
,
S.
, 2003, “
A Review of Solar-Powered Stirling Engines and Low Temperature Differential Stirling Engines
,”
Renewable Sustainable Energy Rev.
1364-0321,
7
(
2
), pp.
131
154
.
15.
Mills
,
D.
, 2004, “
Advances in Solar Thermal Electricity Technology
,”
Sol. Energy
0038-092X,
76
(
1–3
), pp.
19
31
.
16.
Oliveira
,
F. A. C.
,
Shohoji
,
N.
,
Fernandes
,
J. C.
, and
Rosa
,
L. G.
, 2005, “
Solar Sintering of Cordierite-Based Ceramics at Low Temperatures
,”
Sol. Energy
0038-092X,
78
(
3
), pp.
351
361
.
17.
Tschudi
,
H. R.
, and
Morian
,
G.
, 2001, “
Pyrometric Temperature Measurements in Solar Furnaces
,”
ASME J. Sol. Energy Eng.
0199-6231,
123
(
2
), pp.
164
170
.
18.
Mikron Infrared
, 2006, private communication.
You do not currently have access to this content.