TELEVAC MX2A, Instruction Manual

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Instruction Manual MX2A Active Thermocouple Gauge
The atmosphere calibration point allows the gauge to adjust the pressure reading at atmosphere
(760 Torr). This should be used only when the operator knows that the unit is exposed to at-
mosphere or is compared to a reference gauge that is NIST calibrated and reading near 760
Torr.
For users calibrating against a NIST calibrated standard, maximum accuracy for the MX2A can
be achieved by adjusting the unit between 740 Torr and 780 Torr.
D . Resolution High/Low
To reach the resolution high/low screen:
ˆ
Navigate to the calibration screen.
ˆ
Press DOWN three times.
ˆ
Press ENT to unlock the resolution high/low 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 resolution of the MX2A is set to low by default. Under this setting the resolution is determined
by the accuracy of the gauge. The gauge will automatically adjust the resolution based on the
pressure. The MX2A always displays four digits on the calibration screen. For operators who are
looking for more resolution on the measurement screen, the MX2A can be set to high resolution
and will display four digits on the measurement screen.
E . Default
To reach the default screen:
ˆ
Navigate to the calibration screen.
ˆ
Press DOWN four times.
ˆ
Press ENT twice to trigger a reset to the factory defaults.
The default screen resets all calibration point adjustments to the default values. This feature
should only be used when necessary. Warning: RESTORING TO DEFAULT CALIBRATION SETTINGS
VOIDS THE CALIBRATION!
F . Diagnostic
To reach the diagnostic screen:
ˆ
Navigate to the calibration screen.
ˆ
Press DOWN five times.
The diagnostic screen is used by Televac technicians when inspecting the MX2A for any problems.
Under no circumstance does the operator need to access or consider this screen.
G
.
Analog Output Adjustment
To reach the analog output screen screen:
ˆ
Navigate to the calibration screen.
ˆ
Press DOWN six times.
ˆ
Press ENT to unlock the analog output 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 analog output accuracy for the MX2A generally agrees with the digital reading. However,
in extreme temperatures or in significant humidity, the agreement may change slightly. For
uses of the MX2A where the analog output accuracy is critical, an adjustment is available to
ensure accuracy. When making this adjustment use a calibrated voltmeter to measure the analog
output voltage when the MX2A is at a very stable pressure. Compare this voltage reading to the
expected voltage. The expected voltage can be determined based on the formulae in the section
of this manual entitled Analog Output.
email: sales@frederickscompany.com tel: +1 215 947 2500 web: frederickscompany.com mx2a_im rev F 9 of 17