MKS 651C - How To Zero a Sensor

Chapter Six: Remote Operation How To Zero a Senso
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How To Zero a Sensor
Zeroing a sensor allows you to correct any zero offsets.
1. Turn the gas flow off.
2. Fully open the control valve.
3. Wait until the system is pumped down to base pressure.
In order to achieve a proper zero, the pressure of the system must be
lower
than the
resolution of the Baratron used to measure system pressure. If the pressure reading (at
base pressure) is greater than 4% of full range, the sensor will not be zeroed.
4. Issue the following command to zero the sensor:
Z1
ENTER
The system responds by zeroing the sensor. The system pressure reading will be zero.
How To Use the Special Zero
The special zero function is used to zero base pressure in systems where the known base pressure
is not
at
, but
near
zero (as measured by another transducer on the system).
•
To command the special zero function, set your system at base pressure and send the
command:
Z2
value
ENTER
The
value
is expressed as % of full scale pressure.
value
= known base pressure reading
transducer’s full scale
How To Remove the Zero
The remove zero function removes the zero correction factors (
Z1
and
Z2
corrections) stored in
memory, and is used to determine the uncorrected signal from the pressure transducer. Each time
a sensor is zeroed, the offset changes. In some applications it may be important to keep the zero
offset within a specific range.
•
To remove the zero correction, send the command:
Z3
ENTER