MAN0905_Issue 7_07/17
Searchpoint Optima Plus with optional HART
®
output
Operating Instructions
2108M0550
69
Unit does not respond as expected
to test gas
Zero offset
1. Re-zero Searchpoint Optima Plus before repeating
the test (see Maintenance, Bump Test).
Dirty optics
1. Check that the optics are clean and dry. If necessary
clean optics and carry out a soft reset
(see Maintenance, Inspection).
High or low atmospheric pressure 1. Searchpoint Optima Plus does not compensate for
the effects of atmospheric pressure, which can change
the gas reading (see Specification).
Incorrect test gas
1. Check which gas and measuring range the
Searchpoint Optima Plus is calibrated for.
2. Check that the correct test gas and concentration
with an appropriate tolerance are being used.
3. Check that the gas cylinder is not empty.
4. Check that any gas tubing or inlet pipes are not
broken or blocked.
5. Check that the correct flow rates and stabilisation
times are being used (see Maintenance, Bump Test).
Unit is in HART
®
multi-drop mode 1. A unit which is set to HART
®
multi-drop mode will
output a constant 4 mA.
Unit requires calibration
1. If all of the above checks have been done without
correcting the problem, carry out a full calibration.
Output appears to be drifting
Correct response to low level gas
concentration
1. Check the gas concentration where the Searchpoint
Optima Plus is installed using a sensitive portable gas
detector.
Build-up of contamination on
optics, e.g. oil mist, exhaust
fumes, solvents etc.
1. Clean the Searchpoint Optima Plus and carry out a
Reset (see Maintenance, Inspection).
2. If possible, identify and minimise potential sources
of contamination. Contamination can be carried by
steam.
Output appears to be unstable
Electrical interference being
induced on 4-20 mA cabling
1. Check for earth loops. Confirm that the screen is
earthed correctly (see Electrical Installation, Earth
Regimes).
2. Look for noise on the signal using an oscilloscope.
This may give some insight into the potential source.
3. For noisy installations, consider using filtering and
signal processing at the control card.
Poor contacts
1. Check the terminal connections in the junction box.
2. If necessary tighten the connectors.
3. Excessive vibration can loosen connections. If
possible identify and minimise potential sources of
vibration.
14. Problem Solving