OHAUS Navigator Series, Service Manual

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CHAPTER 4 TESTING
Navigator Series Service Manual 21 Ohaus Corporation www.ohaus.com
4.5 PERFORMANCE TESTS
Accurate performance of the Navigator scales is determined by a series of four performance tests.
The displayed readings are compared with the tolerances listed in Tables 4-2 and 4-3. Tolerance
values are expressed in counts. A one-count difference is shown in the last digit on the scale
display.
TABLE 4-2 TOLERANCES
Model Precision (d) Repeatability (d) Linearity (d) (Std.
Dev.)
OCL (d)
NV222 ±1 1 ±2 ±3
NV422
±1 2 ±2 ±3
NV622 ±1 2 ±2 ±3
NV221 ±1 1 ±2 ±3
NV621 ±1 1 ±2 ±3
NV1201 ±1 1 ±2 ±3
NV2201 ±1 1 ±2 ±3
NVT1601M ±1 1 ±2 ±3
NVT2201 ±1 2 ±2 ±3
NVT4201 ±1 2 ±2 ±3
NVT6201
±1 1 ±2 ±3
NVT2200 ±1 1 ±2 ±3
NVT3200M ±1 1 ±2 ±3
NVT6200 ±1 1 ±2 ±3
NVT6400M ±1
1 ±2 ±3
NVT12000 ±1 1 ±2 ±3
NVT16000M ±1 1 ±2 ±3
NVT22000 ±1 1 ±2 ±3
NV123 ±1 5 ±9 ±8
NV223
±1 5 ±9 ±8
NV323 ±1 5 ±9 ±8
NV1202
±1 7 ±6 ±8
NV2202 ±1 7 ±6 ±8
NV3202 ±1 7 ±6 ±8
NVT10201 ±1 5 ±4 ±4
The following performance tests are used to evaluate scale operation before and after repairs. The
scale must meet the requirements specified in each test as well as the specifications listed in Table
4-2. Before proceeding with the following tests, the scale should be calibrated. (See Appendix A)
4.5.1 Precision Test
The Precision Test is a quick test that measures the deviation of a limited number of weight
readings, which should match the specification for each model, listed in Tolerance Table 4-2.
1. Power on the balance. The reading on the display should be 0g.