OHAUS Navigator NV1101, Service Manual

Page: 35 / 58

CHAPTER 4 TESTING
Navigator Series Service Manual 29 Ohaus Corporation www.ohaus.com
Test Procedure:
1. Zero the instrument.
2. Using a test mass approximately half the capacity of the instrument, place the mass on the
center of platform. Record the reading on the worksheet provided.
3. Remove the mass from the platform.
4. Repeat this test starting at Step 1 until you record a total of ten readings
Fill in the worksheet (Table 4-3) with the ten (10) readings .
TABLE 4-3. REPEATABILITY WORKSHEET
n Reading Delta = Reading
– Mean
Delta x Delta
1
2
3
4
5
6
7
8
9
10
n = number of Reading Mean = Sum of readings / 10 Delta = Reading
– Mean
Standard Deviation = Square Root of (sum of (Delta x Delta) / 9)
5. Add the ten readings and divide the total by 10 to find the Mean (average).
6. Mean = (Reading 1 + Reading 2 + Reading 3 + Reading 4 + Reading 5
7. + Reading 6 + Reading 7+ Reading 8 + Reading 9 + Reading 10) / 10
Mean =________
6. Calculate the Delta for each reading and record in the work sheet.
Delta = Reading
– Mean
7. Calculate the Delta x Delta for each reading and record in worksheet.
8. Add the ten Delta x Delta values and divide by 9
9. Calculate the Standard Deviation by applying the square root of the result from step 8.
Standard Deviation
=___________
Note: If the balance does not meet specifications, move it to a suitable location, ensure
that it is level, and try again. If it still does not meet specifications, perform a service
calibration, and try again. (See Appendix B for Service Calibration)