Reading and Interpreting Tolerances
For each range, four tolerances are shown depending on the interval since the previous calibration. During the interval between calibrations, the internal reference of the instrument is expected to drift, as are some other components that affect the accuracy of the final answer.
The accuracy data are presented as the sum of two numbers; one proportional to the reading (displayed value), the other proportional to the range (as shown). To calculate the accuracy of a given reading, multiply that reading by the "ppm of Reading" number (ppm is parts-per-million), then determine which range is being used for the reading and multiply that range by the "ppm of Range" number. Add those two products to determine the accuracy tolerance.
Note: Option 002 indicates a special low-drift internal voltage reference with better specifications.
| 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