OHAUS TA152, Service Manual

Page: 29 / 49

CHAPTER 4 TESTING
4.4.4 Linearity Test
This test is used to determine the linearity of the unit throughout its operating range.
The masses used to perform this test can be utility masses.
NOTE:
The scale must pass the Repeatability and Off Center Load tests, and be calibrated,
before the Linearity Test may be performed.
TABLE 4-2A. LINEARITY TEST MASSES
Capacity &
Readability
200ct x
0.005 ct
150 x
0.01g
200 x
0.01g
300 x
0.01g
300 x 0.1g
400 x
0.01g
500 x 0.1g
Reference Mass 10g 50 50 50 50 100 150
Load 1 10g 20 50 50 50 100 150
Load 2 20g 50 100 150 150 200 250
Load 3 50g 100 150 250 250 300 350
TABLE 4-2B. LINEARITY TEST MASSES
Capacity &
Readability
600 x 0.1g 1500 x 0.1g 3000 x 0.1g 4000 x 0.1g 5000 x 1g 6000 x 1g
Reference Mass 100 500 500 1000 1000 1000
Load 1 200 300 1000 1000 1000 4000
Load 2 400 600 2000 2000 2500 4000
Load 3 500 1000 2500 3000 4000 5000
NOTE:
All masses are nominal values. Be certain to use the same reference mass throughout
the procedure.
1. Place the reference mass on the Scale, record the weight and remove.
2. Place Load 1 on the Scale and press TARE.
3. Place the reference mass on the Scale, record the weight and remove.
4. Place Load 2 on the Scale and press TARE.
5. Place the reference mass on the Scale, record the weight and remove.
6. Place Load 3 on the Scale and press TARE.
7. Place the reference mass on the Scale and record the weight.
8. The difference in the weights of the test mass should be within the tolerance in the
relevant Specification Table in Chapter 1. If not, calibrate (see Appendix A.1) and
repeat the test.
9. If the Scale remains out of tolerance, the Load Cell may need to be replaced.
Ohaus Corporation www.ohaus.com 4-6 Traveler™ Series Scales Service Manual