MKS Baratron 740C, Manual, Page: 53 / 84

Chapter Two: Installation How To Check the Transducer Zero
43
Highest Pressure for Proper Zero Adjustment
Full Scale Range Pressure
10 Torr
< 5 x 10
-4
Torr
100 Torr < 5 x 10 -3 Torr
1000 Torr
< 5 x 10
-2
Torr
30 psia < 1 x 10
-3
psia
100 psia < 5 x 10 -3 psia
500 psia
< 2 x 10
-2
psia
1000 psia < 5 x 10 -2 psia
2000 psia < 0.1 psia
3000 psia < 0.1 psia
Table 18: Highest Pressure for Proper Zero Adjustment
How To Zero a Gage Unit
Standard (non-compound) Gage Units
To properly zero a standard (non-compound) gage unit:
1. Install the transducer in a system with a power supply/readout.
2. Open the process port to local atmospheric pressure.
Note
The “reference” of the transducer is always open to the local atmospheric
conditions. The zero is set only when the Px (process port) is also open to
local atmospheric pressure.
3. Adjust the
ZERO
pot until the readout displays zero (0000).