Setra System 267MR - Manual (Page 9)

2. If unshielded cable is used, an earth grounded metal conduit fitting can
be used to replace the shielded cable.
3. For a sensor with a metal body or enclosure, the body/enclosure must
be grounded to earth. If a protective metal housing is used, the metal
housing should be grounded to earth
4. If a protective plastic housing is used, the housing must be able to with-
stand at least 2 KV from the housing to earth ground, without damaging
the circuit.
4.0. CALIBRATION
The 267 and 267MR transducer is factory calibrated and should require no field
adjustment. Generally, the mounting position will have a zero shift effect on
ranges below 1” WC. Whenever possible, any zero and/or span offsets should
be corrected by software adjustment in the user’s control system. However,
both zero and span adjustments are accessible under the cover of the unit,
below and to the right of the terminal strip. The 267 and 267MR transducer is
calibrated in the vertical position at the factory (mounting tabs vertical).
4.1 Voltage Output Zero Adjustment
While monitoring the voltage between the positive output (+SIG) and common
(GND), and with both pressure ports open to atmosphere, the zero may be ad-
justed by turning the zero adjustment screw. (See Diagram 1 for location of zero
adjustment.) Factory settings are:
Unidirectional Pressure Ranges Bidirectional Pressure Ranges
Zero Adjustment Output Zero Adjustment Output
0.05 VDC (±25 mV) 0-5 VDC 2.5 VDC (±25 mV) 0-5 VDC
0.05 VDC (±50 mV) 0-10 VDC 5 VDC (±50 mV) 0-10 VDC
4.2 Voltage Output Span Adjustment (Complete the zero adjustment
before setting span.)
Span or full scale output adjustments should only be performed by using an
accurate pressure standard (electronic manometer, digital pressure gauge, etc.),
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