OHAUS Defender D100HL, Service Manual

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CHAPTER 4 TESTING
4.5 Performance Tests
Accurate performance of the Defender Bases is determined by two tests. Compare the
displayed readings with the tolerances listed in the Specifications Tables in Chapter 1.
NOTE:
The following performance tests are used to evaluate base operation before and
after repairs. The base must meet the requirements specified in each test as
well as the specifications listed in Table 1-2. Before proceeding with the
following tests, the indicator should be calibrated. (See Section 4.3.)
4.5.1 Off Center Load (Shift) Test
The Shift Test is made before and after a Base has had the Load Cell replaced and adjustments
have been made that affect its performance. The Shift Test verifies that all sections of the Base
weigh within specified tolerance.
If the Base does not pass the Shift Test, verify that the Overload Stops are properly set.
(See Section 3.1.) If the Shift Test cannot be passed, the Load Cell must be replaced.
Prior to starting this test, the Base must be connected to a properly functioning Indicator, with
capacity and readability values set according to the specifications for the Base under test.
1. Place test weights equal to one third of the Base's capacity sequentially at each of
the positions A, B, C, and D, as shown in Figure 4-1. Note the indicator reading at
each position. (For Base capacity, see Table 1-1.)
2. Check the variation between mass weights and indicator reading against specified
Shift Tolerance in Table 1-1.
A
B
C
D
Figure 4-2. Positions A, B, C and D are centered
at each quarter of the base platform.
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