Pyrometer
An infrared pyrometer (Cyclops 160B, 1.6mum, 200..1400degC) , with tripod, is available for contactless temperature measurements through the chamber windows.
For this operating wavelength no special window materials are required, it can see through quartz. However you should not assume that all windows are clean - if a window has been coated by past evaporations, you will under-read the temperature.
Temperature measurement with a pyrometer should be considered reproducible, but poorly calibrated. Proceed with caution.
Emissivities at 1.6mum
Material |
Emissivity, clean |
Emissivity, oxidised |
|---|---|---|
Ag |
0.04 |
0.10 |
Al |
0.09 |
0.40 |
Au |
0.02 |
|
Be |
0.3 |
|
Cr |
0.34 |
0.80 |
Co |
0.28 |
0.65 |
Cu |
0.05 |
0.85 |
Fe |
0.30 |
0.85 |
Graphite |
0.85 |
|
Mg |
0.24 |
0.75 |
Mo |
0.25 |
0.75 |
Ni |
0.25 |
0.85 |
Pb |
0.28 |
0.65 |
Pd |
0.23 |
|
Pt |
0.22 |
|
Si |
0.67 |
|
Sn |
0.28 |
0.60 |
Ti |
0.50 |
0.80 |
W |
0.30 |
Silicon emissivity from this paper
Be emissivity is just the value we’ve always used in the past; I can’t back up that number.
All other values are taken from the Cyclops L user guide