TELEVAC MX2A, Instruction Manual

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Instruction Manual MX2A Active Thermocouple Gauge
2.5.2 Calibration
To reach the calibration screen:
ˆ
Navigate to the measurement screen.
ˆ
Press SEL once.
ˆ
Press the UP and DOWN arrows to navigate between panes under the calibration heading.
To ensure that the unit always displays with the most accuracy, the MX2A includes a number of
operator-configurable calibration points. While the MX2A is factory calibrated, the use of the included
calibration points may become necessary after extended use, contamination, etc. If accuracy is criti-
cal, it is recommended to return the sensor to TELEVAC for NIST-traceable calibration.
Note : Calibration should be performed in the following order: vacuum adjustment, 10 Torr adjust-
ment, 760 Torr adjustment. Failing to calibrate in this order will result in inaccuracies.
Note 2 : CHANGING CALIBRATION SETTINGS VOIDS NIST-TRACEABLE CALIBRATIONS!
A . Vacuum (Zero)
To reach the vacuum screen:
ˆ
The vacuum screen is the first pane of the calibration screen.
ˆ
Press ENT to unlock the vacuum screen.
ˆ
Press UP or DOWN to adjust the reading.
ˆ
When the desired reading is reached, press ENT to save and lock the change.
The vacuum calibration point allows the gauge to adjust the pressure reading at high vacuum
(“zeroing”). This should be used only when the operator knows that the unit is pumping down
below 10
− 4
Torr and the unit reads a non-zero number. When the vacuum is below the range
of MX2A measurement (preferably as low as 10
− 5
Torr), adjust the unit until it blinks between
.0000 and .0001.
For users calibrating against a NIST calibrated standard, maximum accuracy for the MX2A can
be obtained by calibrating the MX2A to .0050 Torr instead of the normal .0000 Torr reading.
B
.
10 Torr
To reach the 10 Torr adjustment screen:
ˆ
Navigate to the calibration screen.
ˆ
Press DOWN one time.
ˆ
Press ENT to unlock the 10 Torr adjustment screen.
ˆ
Press UP or DOWN to adjust the reading.
ˆ
When the desired reading is reached, press ENT to save and lock the change.
The 10 Torr calibration point allows the gauge to adjust the pressure reading at 10 Torr. This
should be used only when the operator knows that the unit under calibration is compared to a
reference gauge that is NIST traceable calibrated and reading near 10 Torr.
C
.
Atmosphere
To reach the atmosphere screen:
ˆ
Navigate to the calibration screen.
ˆ
Press DOWN two times.
ˆ
Press ENT to unlock the atmosphere adjustment screen.
ˆ
Press UP or DOWN to adjust the reading.
ˆ
When the desired reading is reached, press ENT to save and lock the change.
email: sales@frederickscompany.com tel: +1 215 947 2500 web: frederickscompany.com mx2a_im rev F 8 of 17