MKS Baratron 631D, Инструкция по эксплуатации, Страница: 47 / 64

Chapter Four: Operation
39
How To Adjust the Coarse Zero Switch
Note
Use the
COARSE ZERO
switch only if the
ZERO
potentiometer fails to
provide sufficient adjustment.
To adjust the
COARSE ZERO
switch:
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 and the “At Temp Status” LED is glowing green, 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, page, 38,
for the highest recommended pressure levels for proper zero adjustment.
4. Center the Z
ERO
potentiometer located at the top of the transducer by adjusting the screw
to leave an equal amount of adjustment both clockwise and counterclockwise.
5. Remove the plug that covers the
COARSE ZERO
switch. Refer Figure 4: Dimensions of the
Type 631D Transducer, page 32.
6. Turn the
COARSE ZERO
switch to a position that produces the output signal closest to
0.000 Volts.
7. Adjust the
ZERO
potentiometer to bring the output to exactly 0 Volts.
Refer to How To Adjust the Zero Potentiometer, page 38, for more information.
8. Cover the
COARSE ZERO
switch with the plug removed in step 5.