OHAUS Navigator NV212, Service Manual

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CHAPTER 4 TESTING
Navigator Series Service Manual 27 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) OCL
NV212 ±1 2 ±2 ±3
NV311(N or M) ±1 1 ±2 1 MPE
NV511
±1 2 ±2 ±3
NV1101 ±1 2 ±2 ±3
NV2101 ±1 2 ±2 ±3
NV4101 ±1 2 ±2 ±3
NV5101 ±1 2 ±2 ±3
NVL511 ±1 2 ±2 ±3
NVL1101
±1 2 ±2 ±3
NVL2101 ±1 2 ±2 ±3
NV3100(N or M)
±1 1 ±2 1 MPE
NVL5101 ±1 2 ±2 ±3
NVL10000
±1 2 ±2 ±3
NVL20000 ±1 2 ±2 ±3
NVT1601 ±1 2 ±2 ±3
NVT1601(N or M) ±1 1 ±2 1 MPE
NVT3201
±1 2 ±2 ±3
NVT3200(N or M) ±1 1 ±2 1 MPE
NVT6400(N or M)
±1 1 ±2 1 MPE
NVT6401 ±1 2 ±2 ±3
NVT10001 ±1 2 ±2 ±3
NVT16000 ±1 2 ±2 ±3
NVT16000(N or M) ±1 1 ±2 1 MPE
NOTE:
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.
2. Select a mass weighing near the maximum capacity of the balance, and place it on the center
of the Pan. Observe and record the reading.
3. Remove the mass. The reading should return to 0g ± the precision tolerance in Table 4-2.