TELEVAC MX7M, Instruction Manual

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Instruction Manual MX7M Active Gauge
ˆ
Press UP or DOWN until the unit matches the reference in use for calibration.
ˆ
Press ENT to save the adjustment. Press SEL to exit without saving.
Note 1 : Calibration should be performed in the following order: 1 × 10
−
6
Torr adjustment, 1 × 10
−
5
Torr adjustment, 1 × 10
−
4
Torr adjustment, 1 × 10
−
3
Torr adjustment. Failing to calibrate in this order
will result in inaccuracies.
Note 2 : CHANGING CALIBRATION SETTINGS VOIDS NIST-TRACEABLE CALIBRATIONS!
A
.
10
−
6
Torr
The 1
×
10
−
6
calibration point allows the gauge to adjust the pressure reading at 1
×
10
−
6
Torr.
This calibration point should not be use to adjust the gauge reading below a reference pressure
of 5
× 10
−
7
Torr or above 2 × 10
−
6
Torr.
B . 10
− 5
Torr
The 1 × 10
− 5
calibration point allows the gauge to adjust the pressure reading at 1 × 10
− 5
Torr.
This calibration point should not be use to adjust the gauge reading below a reference pressure
of 5
×
10
− 6
Torr or above 2
×
10
− 5
Torr.
C
.
10
− 4
Torr
The 1
×
10
−
4
calibration point allows the gauge to adjust the pressure reading at 1
×
10
−
4
Torr.
This calibration point should not be use to adjust the gauge reading below a reference pressure
of 5
× 10
−
5
Torr or above 2 × 10
−
4
Torr.
D
.
10
− 3
Torr
The 1
×
10
− 3
calibration point allows the gauge to adjust the pressure reading at 1
×
10
− 3
Torr.
This calibration point should not be use to adjust the gauge reading below a reference pressure
of 5
×
10
− 4
Torr or above 2
×
10
− 3
Torr.
E
.
Analog Output Adjustment
The MX7M allows for an offset calibration of the MX7M to provide maximum accuracy for users
where long cable lengths are affecting the accuracy. To calibrate the analog output, adjust
the pressure of the vacuum system to a stable pressure corresponding to the a value near the
maximum analog output. Measure the analog output with a volt meter, compare the displayed
pressure on the gauge to the calculated pressure based on the analog output, and adjust the
calibration until the displayed pressure and calculated pressure match. See section 2.7
2.6.5 Set Points
The MX7M contains two set points for the convenience of the operator. Set point 1 is an N-Channel
60 V MOSFET open collector. It has a maximum current rating of 1 A. The data sheet can be found at
www.vishay.com/docs/69958/si2308bds.pdf . Set point 2 is a relay with a maximum switching voltage
of 220 V DC (250 V AC) and a maximum switching current of 2 A. The data sheet can be found at
www.te.com/catalog/pn/en/1393788-3 .
To modify the set point settings:
ˆ
Navigate to the measurement screen.
ˆ
Press SEL four times.
ˆ
The set point screen contains set point 1 off.
ˆ
To access set point 1 on, set point 2 off, or set point 2 on, press DOWN from the initial set point
screen.
ˆ
When the correct set point is selected, press ENT to unlock the set point adjustment screen.
email: sales@frederickscompany.com tel: +1 215 947 2500 web: frederickscompany.com mx7m_im rev C 11 of 23