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Troubleshooting (Continued)
:
Q.
What if there is no analog output?
Verify that the signal and ground wires are secured to the terminal block.
Q.
What if the OnGuard Smart is hooked up to a DCS that is reporting unexpected values?
If the output channels are hooked up, eight wires must be secured in the proper positions on the
terminal block. Verify the reading at the terminal block and compare them to the reported values
on the DCS or BMS. If a discrepancy exists, the wiring is not correct.
Q.
What if the cumulative corrosion fluctuates instead of continually increasing?
This occurrence is normal for the corrosion sensors. The sensors are extremely sensitive and
even water vapor or microscopic dust particles will cause minor fluctuations in the readings.
Control of temperature, relative humidity and vibrations will help minimize fluctuations. The scale
selected to graphically display the data, if a narrow range, can also accentuate the fluctuations.
Q.
What if the cumulative readings don’t match the results of coupons in the same environment?
Be sure the coupons are placed as close to the OnGuard Smart as possible. The OnGuard Smart
zeros out any existing corrosion on the sensors during initial power-up. Coupons as prepared per
the ISA Standard (S71.04) generally have background reading from 50 to 150 angstroms. The
coupon value should be corrected for background corrosion before making any comparisons.
Q.
What if the OnGuard Smart has been moved to a new location and the corrosion values seem to
have changed?
The OnGuard Smart is designed to be permanently mounted. Any shaking or jostling may affect
the corrosion sensors. If the OnGuard Smart is moved, remount, wire and install new sensors.
Q.
What if the unit is in a continuous alarm state?
Check the high and low levels for the temperature and relative humidity. The units are shipped
with factory defaults, but these defaults are often changed when the owner has become familiar
with the operation of the unit.
Also, check the incremental limits for copper and silver corrosion
