Reading and Interpreting Tolerances
PRESET, NPLC, and MATH NULL are all settings of the instrument's internal logic that can be selected from the front panel or through program commands from an attached computer.
You can see that if you don't read all of the details of the specifications carefully and understand them completely, it won't be possible to use this sophisticated instrument correctly to its full capabilities.
Make sure to carefully read the specifications that go with the table at right.
| Accuracy1 [ppm of Reading (ppm of Reading for Option 002) + ppm of Range] | |||||
|---|---|---|---|---|---|
| Range | 24 Hour2 | 90 Day3 | 1 Year3 | 2 Year3 | |
| 100 μV | 2.5 + 3 | 5.0 (3.5) + 3 | 9 (5) + 3 | 14 (10) + 3 | |
| 1 V | 1.5 + 0.3 | 4.6 (3.1) + 0.3 | 8 (4) + 0.3 | 14 (10) + 0.3 | |
| 10 V | 0.5 + 0.05 | 4.1 (2.6) + 0.05 | 8 (4) + 0.05 | 14 (10) + 0.05 | |
| 100 V | 2.5 + 0.3 | 6.0 (4.5) + 0.3 | 10 (6) + 0.3 | 14 (10) + 0.3 | |
| 1000 V4 | 2.5 + 0.1 | 6.0 (4.5) + 0.1 | 10 (6) + 0.1 | 14 (10) + 0.1 | |
1 Specifications are for PRESET; NPLC 100
2 For fixed range (> 4 min.) MATH NULL and T cal ± 1 ° C.
3 Specifications for 90 day, 1 year and 2 years are within 24 hours and ± 1 °C of last ACAL; T cal ± 5 ° MATH NULL and fixed range. Ppm of Reading specifications for High Stability (Option 002) are in parentheses. Without MATH NULL, add 0.15 ppm of Range to 10V, 0.7 ppm without MATH NULL, and for fixed range less than 4 minutes add 0.25 ppm of Range to 10V, 1.7 ppm of Range to 1V and 17 ppm of Range to 0.1V. Add 2 ppm of reading additional error for factory traceability to US NIST. Traceability error is the absolute error relative to National Standards associated with the source of last external calibration.
4 Add 12 ppm X (√in/1000)2 additional error for inputs > 1000
Conditions:
Following 4 hour warm-up. Full scale to 10%of full scale.
Measurements on the 1000 V range are within 5%of the initial measurement value and following measurement settling.
Tref is the starting ambient temperature.
Measurements are made on a fixed range (>4 min.) using accepted metrology practices.