chemical solutions, equipment or interferences.
The U.S. Environmen-
tal Protection Agency recommends as many as seven comparison tests for
a dependable indication. Bear in mind the sample dilution with a
corresponding constant will offset a heavy concentration of the
substance being tested for.
Exceeded shelf life in the field can be anticipated as the
greatest cause of test unreliability.
The analyst will have to use
these reagents as an indication until the reagent can be compared to a
known sample or a standard solution.
Replacement chemicals from other sources.
Other standard sol-
utions and additional chemicals may be obtained or test results
compared using military or civilian facilities as convenient, to
supplement the WQAS.
Refurbishment of specified supplies must be from
the designated source or equal.
Operating Checks on Meters (Summary).
Operating controls (table 2-6).
Power connections (para 2-18a(2)(a)).
Filtering wedge (para 2-18a(2)(a)).
Mode of control, wavelength dial (para 2-18b).
Proper setup (para 2-18c).
After use checks (para 2-18d).
(2) Conductivity meter.
(a) Operating controls (para 2-22f(1)(a)).
precautions and cleaning of cell (para
Before you use table 3-2, be sure you have per-
formed all applicable operating checks.