ADV Service Manual P/N 83020790 A
Ohaus Corporation
www.ohaus.com
25
and is in accordance with the tolerances listed in Tables 4-2 and 4-3. The masses used to perform this test must
meet or exceed ASTM Class 1 Tolerance.
NOTE
:
The balance must pass the Off-Center Load test and Precision Test before
the Centered Load Test is performed.
This test is used to determine the linearity of the balance throughout its operating range.
Tables 4-4 and 4-5 lists the suggested masses to be used for checking linearity on each Balance model.
TABLE 4-4. CENTER LOAD TEST MASSES - PRECISION
CAPACITY
AR
153
AR
223
AR
323
AR
423
AR
423D
AR
522
AR
1502
AR
2202
AR
3202
AR
4202
AR
4202D
AR
4201
Ref.Wt. 1g 1g 1g 1g 1g 1g 1g 1g 1g 1g
1g
1g
Load
1
20g 10g 30g 10g 10g/10g 50g
200g
250g
300g
100g 100g/10g 400g
Load
2
75g 50g 120g 50g 50g/50g 200g 750g 1000g 1200g 1000g 1000g/500g 1000g
Load
3
100g 100g 200g 200g 200g/75g 350g 1000g 1700g 2000g 2000g 2000g/750g 2000g
Load
4
150g 200g 300g 400g 400g/100g 500g 1500g 2000g 3000g 4000g 4000/1000g 4000g
TABLE 4-5. CENTER LOAD TEST MASSES - ANALYTICAL
CAPACITY AR64 AR124 AR224
Ref.Wt. 1g
1g 1g
Load 1
10g
10g
10g
Load
2
20g 25g 100g
Load
3
40g 50g 150g
Load 4
50g
100g
200g
A 1g calibration mass is recommended for the reference mass. All masses are nominal values. HOWEVER, BE
CERTAIN TO USE THE SAME REFERENCE MASS THROUGHOUT THE PROCEDURE.
Before beginning:
• Perform calibration.
Preliminary Weighings
Using the Load 3 and Load 4 weight values (Table 4-3 or 4-4), perform some preliminary weighing and make sure the
display returns to zero after weighing.
1. Place Load 3 on the center of the Platform, read the displayed weight, then remove Load 3. If the display
does not return to zero, press
and repeat this.
2. Repeat step 1 using Load 4.
After performing preliminary weighing, proceed with checking Linearity. If the balance does not return to zero,
it must be repaired.
Test
1. Place the reference mass on the center of the Platform and record the exact value (all decimal places)
displayed.
2. Remove the reference mass and verify that the display returns to zero. If it does not, disregard the reading,