TM 5-6630-215-12
(3) RE1O Range Extender - The RE1O Range Extender is a small
insert which can be pushed into the sample filled cell cup.
Its
purpose is to temporarily increase the range by 10 times.
Reducing
the effective cell size.
(4) Procedure - Total Dissolved Solids - 0.50, 0-500 and 0-5000
ppm.
(a) Rinse the built-in cell cup three times with the water to
be tested and then fill with the water to be tested.
(b) Select the desired range.
(c) Push the button on the front of the instrument, the meter
will indicate the total dissolved solids in parts per million.
(5) Procedure - Total Dissolve Solids O 0-50,000 ppm.
Whenever
the meter reading is off scale (pointer contacts high stop) on the
maximum range:
(a) Thoroughly rinse the range extender three times by insert-
ing the extender into the cell cup which is refilled with a fresh
sample each time.
Push the extender into a fresh sample filled cell
cup seating the o-ring seal.
(b) Operate the instrument as in steps (b) and (c) above.
Multiply the meter reading by 10 to obtain the total dissolved solids
in the sample.
(c) For maximum accuracy, repeat the complete test with fresh
test water.
(d) Upon completion of tests, remove the range extender and
thoroughly rinse the cell cup and extender with deionized water.
This
is extremely important when the instrument is also used to test high
purity water.
g.
Hardness Test Kit (Range O mg/l to 9000 mg/l) (fig. 2-18).
(1) Hardness is defined as a total characteristic of water which
represents the total concentration of calcium and magnesium expressed
as their calcium carbonate equivalent.
When other polyvalent metal
ions are present in significant amounts they are also determined and
reported as hardness.
(a) The hardness of water was originally defined in terms of
its ability to precipitate soap.
Calcium and magnesium ions are the
principle causes though iron, aluminum, manganese, strontium, zinc,
and hydrogen ions are capable of producing the same effect.
High
concentrations of the latter ions are not commonly found in natural
waters. Hardness concentrations were originally expressed as grains
per gallon but are not commonly reported as milligrams per liter (1
gr/gal. = 17.16 gm/l).
2-71
