Section 5 – Sensor Calibration
25
Section 5. – Sensor Calibration
5.1 Temperature
Calibration
The temperature readout must be calibrated before attempting pH or ORP calibration. The decimal
point is replaced by a “
∗
” if the reading is not calibrated.
5.1.1 Temperature Calibration Procedure
1. Switch the pool pump OFF with the Pump Timer function (see section 3.6), and unplug it from
the
POOL PUMP
socket.
Remove the ORP/Temperature sensor from its Tee fitting. For installations where this fitting is
below the level of the pool, a 6.5mm or 1/4” bung can be fitted to stop the water flow.
2. Press
the button to place the
easyCHEM 770
into Standby mode.
3. Plug the ORP/Temperature sensor into the
ORP Probe
socket (if not already connected).
4. Place the sensor into a beaker of room temperature water alongside a good quality mercury
thermometer. Stir the sensor and the thermometer gently to ensure an even temperature
throughout the beaker.
5. When the Temperature reading has fully stabilised, select Temperature Calibration
(Press
, select ‘
→
Calibrate
’, then select ‘
→
Cal Temp
’.)
The Temperature Calibration screen is now displayed. For example…
25.0
o
c Temp Cal.
26.0
o
c
↑↓
Enter
6. Use
the
and
keys to enter the same temperature as measured by the mercury
thermometer.
7. Press to calibrate the temperature readout.
Alternatively, press
to abort temperature calibration.
8. The Temperature readout of the
easyCHEM 770
is now calibrated. The
easyCHEM 770
will
now prompt you to re-fit the probe into its Tee fitting…
Re-Fit Probes
into Pipe Enter
9.
Re-fit the probe into its Tee fitting, as per section 2.2.
Return the pool pump to its normal Pump Timer setting, as per section 3.4.
Press
to return the easyCHEM 770 to Automatic dosing when finished calibrating.
5.1.2 Temperature Calibration Notes
1. The
easyCHEM 770
has an allowable Offset range of –10.0 to +10.0
O
C
. If calibration fails due
to the Offset being outside these limits, then please consult the Troubleshooting guide (section
7.5) for possible remedies.
2. Temperature calibration information is retained in memory when the
easyCHEM 770
is
switched off, even when the power supply is removed.
3. Temperature does not need to be re-calibrated unless the ORP/Temperature sensor is
replaced or the unit is re-set.
