Off Stack Zero Calibration - Emerson OPM 3000 Instruction Manual

Instruction Manual
IM-105-3000, Rev 2.0
November 2008
OFF STACK ZERO
CALIBRATION
This procedure may be used if:
• A clear stack condition is not possible, and the zero appears to be
incorrect.
• The flange to flange distance on site is different than the original factory
set up.
1. Remove the transceiver and retro reflector from the hinge pins.
2. Install the system on test stands at the correct flange to flange distance
plus 11 in. (279 mm).
The additional 11 in. (279 mm) compensates for air plenum spacing, as
the air plenums are not used for the off stack zero calibration. If test
stands are not available an alternate method is to use 3 in. pipe flanges
with air plenums installed. Contact the factory for air plenum availability.
Set the spacing between the 3 in. pipe flanges exactly the same as the
flange-to-flange measurement.
3. Clean transceiver and retro reflector windows.
4. The retro reflector must be level.
5. Follow the instructions for "On Stack Zero and Span Calibration" in
Section 3: Startup and Calibration.
OPM 3000
4-5