MKS Baratron 631D, Инструкция по эксплуатации, Страница: 46 / 64

Chapter Four: Operation
38
How To Adjust the Zero Potentiometer
To adjust the
ZERO
potentiometer:
1. Install the transducer in a system and connect a power supply/readout.
2. Power the transducer and allow it to warm up and stabilize.
Note
Allow 2 hours for units to warm up. Ensure that the transducer is fully
stabilized before you adjust the zero.
3. Pump the unit down to a pressure below its resolution.
For best results, pump the transducer while it is warming up. Refer to Table 7 for the
highest recommended pressure levels for proper zero adjustment.
Zeroing Pressure for 631D Transducer
Sensor Full Scale (Torr) Pressure for Zeroing (Torr)
1 < 0.5 x 10 -5
2 < 1.0 x 10
-5
10
< 5 x 10
-4
30 < 1.5 x 10
-3
100
< 5 x 10
-3
1000 < 5 x 10
-2
Table 7: Highest Pressures Suggested for Proper Zero Adjustment
4. Adjust the
ZERO
potentiometer with a small screwdriver until the readout displays zero
(0.000). Typically, the
ZERO
potentiometer provides ample control under normal conditions.
However, if the
ZERO
potentiometer fails to provide sufficient adjustment, additional zero
range capability is available with the
COARSE ZERO
switch, located on the side of the unit
(refer to Figure 2: Top View of the Type 631D Transducer, page 30, or Figure 3: Top View
of the Type 631D Transducer With Optional Relay System, page 31, for location of the
ZERO potentiometer and coarse zero switch.) Refer to
How To Adjust the Coarse Zero
Switch , page 39, for more information.