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Sheaths
Sapphire, quartz or metal tubes used to protect the costly and fragile
lightpipes. BASF recommends using a sheath to protect the lightpipes from
breakage and deposition. BASF offers a wide range of standard and custom
sheaths, including gas-purged sheaths for deposition processes.
Speed
The response time of the electronics (versus bandwidth, which is the “cutoff”
frequency of the instrument).
EXACTUS
®
instruments can measure
temperature from one reading per minute up to 1,000 readings per second.
These discrete readings are transmitted digitally.
Resolution
The smallest detectable increment of measurement. Resolution is usually
limited by electrical noise and the number of bits of the Analog to Digital
conversion. Resolution is always a function of the measurement speed
(bandwidth) and the temperature being measured. Generally, the slower the
measurement, the higher the resolution. Also the higher the temperature, the
higher the resolution. BASF's resolution for two different wavelengths can be
seen in the following graph. At temperatures above about 300°C the
EXACTUS
®
resolution is 0.001°C.
Temperature Resolution
0.00
1.00
2.00
3.00
4.00
5.00
25
50
75
100
125
150
175
200
225
250
275
300
325
W afer Temperature °C
R
e
s
o
lu
ti
o
n
°
C
1.6 µm wavelength
0.9 µm wavelength
0.01
