4.1Mounting ST 3000 Transmitter, Continued
ATTENTION | The mounting position of a model STA122 or STA922 Absolute |
| Pressure Transmitter or a model STD110 Draft Range Differential |
| Pressure Transmitter is critical as the transmitter spans become smaller. |
| A maximum zero shift of 2.5 mm Hg for an absolute transmitter or 1.5 |
| in H2O for a draft range transmitter can result from a mounting position |
| which is rotated 90 degrees from vertical. A typical zero shift of 0.12 |
| mm Hg or 0.20 in H2O can occur for a 5 degree rotation from vertical. |
Precautions for Mounting Transmitters with Small Absolute or Differential Pressure Spans
To minimize these positional effects on calibration (zero shift), take the appropriate mounting precautions that follow for the given transmitter model.
For a model STA122 or STA922 transmitter, you must ensure that the transmitter is vertical when mounting it. You do this by leveling the transmitter
Figure 6 Leveling a Model STA122 or 922 Absolute Pressure Transmitter.
Models STA122 and STA922
Center
Section
Process
Head
Position spirit balance on center section of meter body only.
Continued on next page
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