MAN0905_Issue 7_07/17
Searchpoint Optima Plus with optional HART
®
output
Operating Instructions
2108M0550
65
Note: If the gas reading is not acceptable for the application, re-zero the Searchpoint Optima Plus and
repeat the test.
13.6 Re-zero Searchpoint Optima Plus
Re-zero Searchpoint Optima Plus if it has given an unexpected response to a gas test. In most cases a re-
zero will restore accuracy and a full span calibration is not required.
Caution: During this procedure the 4-20 mA output will be inhibited automatically. If the procedure is
aborted, ensure that the unit is not left in Inhibit mode.
1. Select
Device Setup
.
2. Select
Calibrate
.
3. Select
Gas Calibration
.
4. The display shows a warning message, press
OK
.
5. Ensure that there is zero gas present in the vicinity of the Searchpoint Optima Plus. If necessary, fit a
Gassing Cover and apply zero gas.
6. When the gas reading on the display is stable press OK to initiate the Zero Calibration and then wait for
approximately 15 s. The 4-20 mA output will be inhibited automatically at this time.
7. The display shows a message that the Zero Calibration was successful and offers to exit without a Span
Calibration. Select
Yes
and press
Enter
.
8. The display shows a note that the Searchpoint Optima Plus will return to normal operation,
press
OK
.
9. Return to the Welcome screen.
13.7 Calibration
Searchpoint Optima Plus is factory calibrated and does not require routine calibration. In most cases, a
re-zero will correct any inaccuracy in the gas reading. It is strongly recommended that a span calibration is
not carried out.
In the unlikely event that a span calibration is required, use a cylinder of the target gas, of approximately
50 %FSD, with an accuracy of at least ± 2 %.
Note: Searchpoint Optima Plus will accept a span calibration gas concentration of between 30 %FSD and
125 %FSD, however this facility is reserved for use in specialist applications.
Do not calibrate Searchpoint Optima Plus during periods of very high or low atmospheric pressure, very
strong winds or storms.
Caution: Gas readings will be generated during this procedure. The 4-20 mA output will be inhibited
automatically. If the procedure is aborted, ensure that the unit is not left in Inhibit mode.
Note: The unit should be powered up for 1 hour before a calibration is done.
1. Using a ½ inch / 13 mm A/F open ended spanner, unscrew the two retaining nuts and remove the
13. Maintenance using HART
®
Communications
