Spectra Watermakers Newport 1000, Installation & Owner'S Manual

Page: 43 / 70

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Salinity Probe Calibration:
Salinity is a measurement of TDS, total dissolved solids in liquid: these solids will conduct elec-
tricity to varying degrees. A special probe is used, with two electrical contacts in it, to determine
the resistance to the flow of electricity in the liquid.
In the Spectra Watermakers systems, the salinity probe is located just before the diversion valve,
at the output of the RO membrane. This way we can look at the salinity level of the product water
before deciding to either reject the water or accept it and divert it into the holding tank.
The salinity level in parts-per-million can be seen either through the salinity meter in the soft-
ware, or a jumper can be added to the MPC board in the ‘calibrate’ position, where it can then be
seen on the LCD display (rather than a bar graph). After adding the jumper, it may be necessary
to cycle through the different LCD displays until the display reads ‘salinity.’
Procedure:
1. Make sure the Calibrate jumper is plugged on both “JP-1” terminals of the MPC-3000 Board.
2. Start the system and after the salinity stabilizes, test the product water with a calibrated hand
held tester.
3. Locate the MPC calibration trimmer potentiometer on the board below the salinity probe
jack. Adjust until the display PPM matches the PPM reading from the hand held salinity
monitor. Turning the trim pot clockwise will lower the salinity reading, and counter-
clockwise will raise it.
4. Shut the system down and disconnect the jumper on the MPC board.
If a hand held meter is not available you can remove the probe and dip it into a known calibrated
solution. This can be obtained from Spectra.