Figure 9 Leveling A Model Sta122 Or Sta922 Absolute Pressure Transmitter - Honeywell ST 3000 User Manual

4.2 Mounting ST 3000 Transmitter,
ATTENTION
Precautions for
Mounting
Transmitters with
Small Absolute or
Differential Pressure
Spans
Figure 9 Leveling an Absolute Pressure Transmitter.
30 ST 3000 Release 300 and SFC Model STS103 User's Manual
The mounting position of a model STA122, STA922, STA12L, or
STA92L 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 inH 2 O 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 H 2 O 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 transmitter
model.
For a model STA122, STA922, STA12L, or STA92L transmitter, 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.
Leveling Absolute Pressure models
Position spirit balance on
center section of meter
body only.
Continued
Center
Section
Process
Head
Cont'd
Continued on next page
February 2012