LEYBOLD 230035V02, Руководство по эксплуатации

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18 300544652_002_C1 - 11/2016 - © Leybold
Sensor gas dependence
The sensor technology is based on measurement of thermal conductivity and consequently its reading depends on
gas and gas concentration.
The transmitter sensor is per factory default calibrated for Nitrogen gas and shown below is the TTR 91 N and
TTR 96 N MEMS Pirani reading for different gas types. Be aware that when measuring in environments where
other gases than nitrogen (calibration gas) are present, the readings can deviate from the true pressure.
In the range below 1 mbar, the pressure indication is linear. For gases other than air, the pressure can be
determined by means of a simple conversion formula:
𝑝
𝑒𝑓𝑓
= 𝐶 . 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑟𝑒𝑎𝑑𝑖𝑛𝑔
For which:
Gas type Calibration factor C Valid range (mbar]
He 1.4 3∙10
-3
to 0.3 mbar
Ar 1.57 10
-3
to 1 mbar
H
2
0.84 3∙10
-3
to 0.2 mbar
Air, O
2
, CO, N
2
1 3∙10
-3
to 0.3 mbar
These conversion factors are average values.
1E-4
1E-3
1E-2
1E-1
1E0
1E1
1E2
1E3
1E-4 1E-3 1E-2 1E-1 1E0 1E1 1E2 1E3
Ac
tu
al
g
as
p
re
ss
u
re
, mba
r
Transmitter reading, mbar
Air (50%
Humidity)
Argon
Helium
Hydrogen