2-15. OPERATION OF AUXILIARY EQUIPMENT-cont.
Always start with meter set in the 1000 mode. If you use a lower mode first, you may
damage the meter.
The TDS meter is factor calibrated and suitable for use when treating fresh (lake, stream,
pond, river) water. When treating seawater and brackish water, it is necessary to
recalibrate the meter. If your meter has both 442 and NaCl internal standards
stamped on the bottom plate, obtain a standard sodium chloride (NaCl) solution
(ARMY-SC-4610-97-CL-E16); and refer to subpara. (3).
Recalibration instructions for meters with both internal standards (442 and NaC1) stamped on the
bottom of the meter.
Set mode switch to S (internal standard).
Remove bottom plate to gain access to master calibration control.
Press indicator button and hold it in.
Adjust the master calibration control with your finger until meter reads same as the value
stamped on the bottom plate for the water you will be treating (442 for fresh water and
NaCl for seawater).
Release indicator button.
Replace bottom plate.
Recalibration instructions for meters with 442 internal standard only stamped on
Obtain a standard sodium chloride (NaCl) solution and note the ppm (parts per Million)
value printed on bottle.
Remove snap-in disc or bottom cover of TDS meter to gain access to the master
Rinse cell cup three times with the standard sodium chloride (NaCl) solution, then fill