Instruction manual
SM425 INSTRUCTION MANUAL 12.0 TROUBLESHOOTING
used for blowback scheduling. If you use this function check / correct the date and time every time you
turn on the power until the alarm has been cleared.
Contact your Teledyne Monitor Labs service representative.
<Corrective Action>
The battery can not be replaced by the user.
Battery life varies with environmental conditions.
* There is no battery draw if power is applied to the instrument continuously. Battery life is typically abo
ten years. However there will be battery draw during the time
ut
interval between shipment from the factory
and site installation.
* If power is not applied to the instrument, at ambient temperatures of 20 to 25°C the battery life is
typically 5 years. In the range -30 to +70°C the battery life is typically 1 year.
12.3 Corrective Actions for Measurement Errors
1. The me ured value is higher than the true value.
2. The measured value is lower than the true value.
unexpected values.
1. An increase in process gas pressure from the process pressure at the time of calibration. The
change in the oxygen concentration, X, is shown by the following expression:
X=Y [1+ (Δp/101.30)]
O
2
).
fluctuations in oxygen concentration due to pressure:
o aintain constant process pressure
2
s
caused by changes in the moisture content of the
process as.
3. Calibration gas (span gas) is leaking into the detector through the calibration gas tubing. Verify
k solenoid valves used in automatic calibration.
Measurement errors occur when:
as
3. The measured value shows abnormal or
12.3.1 Measured Value Higher Than Actual Value
<Causes and Corrective Actions>
Where Δp, in kPa, is the change in the process gas pressure from the pressure at time of
calibration and Y is the oxygen concentration measured at the calibration pressure (vol%
In order to minimize
M
o Calibrate the analyzer at the average process pressure.
2. Significant increase in the moisture content of the calibration gases. A large change of moisture
in reference air may cause an error in the measured oxygen concentration value (vol% O ). This
may occur if ambient air is used as the reference gas. In order to minimize fluctuations in oxygen
concentration due to moisture, use a reference gas whose moisture content is constant such a
instrument air. Small fluctuations can also be
g
the integrity of tubing joints and the needle. Chec
onfirm that manual valves are fully closeC d.
4. The reference gas and process gases are mixing. When the difference between oxygen partial
pressures on the sensor anode and cathode sides decreases, the measured (process) value
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