4.2 Mounting SMV 3000 Transmitter, Continued

ATTENTION

Precautions for Mounting Transmitters with Small Differential Pressure Spans

The mounting position of an SMV 3000 Transmitter is critical as the transmitter spans become smaller for the absolute and/or differential pressure range. A maximum zero shift of 0.048 psi for an absolute pressure range or 1.5 in H2O for a differential pressure range can result from a mounting position which is rotated 90 degrees from vertical. A typical zero shift of 0.002 psi or 0.20 in H2O can occur for a 5 degree rotation from vertical.

To minimize these positional effects on calibration (zero shift), take the appropriate mounting precautions that follow for the given pressure range.

For a transmitter with a small differential pressure span, you must ensure that the transmitter is vertical when mounting it. You do this by leveling the transmitter side-to-side and front-to-back. See Figure 9 for suggestions on how to level the transmitter using a spirit balance.

You must also zero the transmitter by adjusting the mounting position of the transmitter. Refer to start-up procedure in Section 7 for SMV 3000 transmitter model SMA110 and transmitters with small differential pressure spans.

Figure 9 Leveling a Transmitter with a Small Absolute Pressure Span.

Spirit

 

Balance

Process

 

 

Head

 

Center

 

Section

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Image 35
Honeywell SMV 3000 user manual Leveling a Transmitter with a Small Absolute Pressure Span