Rosemount 755, Instruction Manual

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M
ODEL
755 O
XYGEN
A
NALYZER
2-10
748183-H Rosemount Analytical
November 1997
b. Adjust SPAN control for display or recorder reading exactly fullscale. If the
fullscale setting cannot be reached, then set to a reading higher than the
desired alarm setpoint.
c. Set ALARM 2 calibration adjustment, R67, to its clockwise limit. Rotate R67
counter-clockwise, the minimum amount required to energize ALARM 2,
relay K2. Verify that the alarm has been energized with the ohmmeter on the
relay contacts (Figure 2-7).
7. Setpoint adjustment of ALARM 1, HIGH.
a. With span gas flowing, adjust SPAN control to read desired alarm setpoint
on display or recorder.
b. Rotate setpoint adjustment, R64, clockwise to energize relay.
c. Check this setting by adjusting the SPAN control to lower the output below
the setpoint. This will de-energize the relay. Rotating R64 above the setpoint
will energize the relay.
8. Setpoint adjustment of ALARM 2, LOW.
a. With span gas flowing, adjust the SPAN control to read desired alarm
setpoint on display or recorder.
b. Rotate setpoint adjustment, R68, clockwise to energize relay.
c. Check setting by adjusting the SPAN control to lower the output below the
setpoint. This will energize the relay. Rotating R68 above the setpoint will
de-energize the relay.
2.5 CALIBRATION GASES
Calibration gas cylinders are under pressure. Mishandling of gas cylinders
could result in death, injury, or property damage. Handle and store cylinders
with extreme caution and in accordance with manufacturer instructions. Refer
to General Precautions for Handling and Storing High Pressure Gas Cylinders,
in the rear of this manual.
Analyzer calibration consists of establishing a downscale calibration point and an
upscale calibration point.
Downscale calibration may be performed on a range that will be used during sample
analysis. For maximum precision, however, it should be performed on the range of
highest sensitivity, i.e., most narrow span.
Preferably upscale calibration should be performed on a range to be used in sample
analysis. In some applications, however, it may be desirable to perform upscale
WARNING: HIGH PRESSURE GAS CYLINDERS