OHAUS NV212 Service Manual

Also see for Navigator NV1101: Instruction manual Instruction manual

Contents

OHAUS NV212 Service Manual Manual pdf 34 page image

CHAPTER 4 TESTINGOhaus Corporation www.ohaus.com 28 Navigator Series Service Manual4. Repeat this test three times. The readings should be within tolerances. If so, the balancepasses the Precision Test.5. If the deviation for any set of readings (using the same mass placed on the center of the Pan)is greater than the tolerance listed in Table 4-2, the balance does not meet the precisionspecification. Inspect and correct the following areas:– Check for mechanical obstructions. Any foreign object touching any part of the movingassemblies will cause a balance to fail the Precision Test. Inspect and correct asnecessary.– If the scale does not meet specifications, move it to a suitable location, ensure that it islevel, and try again. If it still does not meet specifications, perform a service calibration, andtry again. (See Appendix B for Service Calibration.)– If the scale does not pass this test, the Load Cell may need to be replaced.4.5.2 Repeatability TestThe repeatability specification is defined as the Standard Deviation value derived from a set ofweight readings. This test uses more weight data than the Precision Test and will allow foroccasional weight deviations due to testing variations.Requirements:– To perform this test a single mass must be used for all readings.– The test mass should be approximately ½ of the capacity of the instrument.– Wear gloves when handling the mass.Set Up:Before starting a repeatability test, set up the instrument as follows.Enter the service menu (see appendix B.1) and adjust and record the following settings:A. Set the Stability setting to 0.5d (its lowest setting).B. Set the Filter level to L2 (close to mid range).C. Set the AZT (Auto Zero Tracking) to .5d (its lowest setting). Do not turn it off.Enter the User Menu (see 1.8.1) and adjust the following settings:A. Set the instrument to display the same units as the performance specifications.(Usually kg, g, or mg)Record Settings:Stability Setting = ____________Filter Level Setting = ____________Auto Zero Tracking Setting = ____________Displayed Units = ____________Mass Used = ____________