TM 10-4610-232-12
(2)
The instrument may be operated on a rechargeable battery. The unit does not require any warm-up time before taking
readings. Turn unit OFF between readings for longer battery life between recharges.
NOTE
The turbidity meter provides up to 4-1/2 hours of constant operation as a portable, battery-
operated unit between charges.
(3)
The instrument may be operated while battery charger is being used.
c.
Adjustment Prior to Use. Operating adjustment is checked by the operator each time unit is used. This is a minor adjustment
and is checked as follows:
CAUTION
Fingerprints, grease, dirt and water on the reference standard will cause incorrect readings
(1)
Remove reference standard (7) (0.2 NTU) from case and carefully wipe clean.
(2)
Remove black light shield (4). Place reference standard in optical well (11). Place black light shield over well.
(3)
Set range selector (2) to 20.
(4)
Adjust reference adjust knob (8) until meter (9) reads 0.10. Unit is now ready for use in all ranges.
d.
Use of Meter. To make a measurement of a sample use the following procedure:
CAUTION
If instrument has been in cold temperatures [below 10° C (50° F)] and brought indoors it
should be allowed to warm up before use, since condensation may form on lenses. Leaving
case open and the instrument ON for 30 minutes will help it warm up faster.
NOTE
Make sure the inside of the cuvette is clean.
(1)
Clean one of the cuvettes (10) by rinsing several times with the water to be tested.
(2)
Fill cuvette to top. Replace cap.
CAUTION
Be careful not to scratch cuvette.
(3)
Wipe cuvette clean and dry.
(4)
Rotate cuvette to remove all air bubbles.
(5)
Remove black light shield. Place cuvette in well (11) with light shield (4) over the cuvette.
(6)
Set the range setting to lowest setting where the indicator stays within scale. Record reading after reading stops
changing.
NOTE
Critical measuring area of sample cuvettes is the 3/4 in. band starting 5/8 in. above bottom.
Keep this area clean and free of scratches. Handle by top part above band only as shown in
Figure 2-13
NOTE
Moisture may form on cuvette sides. This results in an incorrect high reading. If noted,
wipe again and repeat measurement.
e.
Meter Care. Portable turbidity meter should not be serviced in the field. Any major problems should be taken care of by
maintenance personnel. Keep instrument clean and dry. Do not drop instrument.
2-26 Change 12
