Fluke 1750 Fluke 1750 Calibration Manual - Page 22

1750 Calibration Manual Applie d Voltage [Vrms] 800 850 900 950 1000 Expected Reading [Vpk] 1131 1202 1273 1344 1414 Table 8. Impulse Verification Inputs Channel Measured Magnitude |Vpk| AN (A) BN (B) CN (C) NG (N) NG (G) Limits [Vpk] ± 77 ± 80 ± 84 ± 87 ± 91 Calibration Required Equipment The required equipment and cables for calibrating the Recorder are listed in Tables 2 and 3. XWWarning To avoid electrical shock, personal injury, or fire: • Do not perform the calibration procedures or calibration verification tests described in this manual unless you are qualified to do so. • Repairs or servicing should be performed only by qualified personnel. Calibration Adjustment The Recorder features closed-case calibration adjustment using known reference sources. During calibration, the Recorder measures the applied reference source, calculates correction factors, and stores the correction factors in nonvolatile memory. Perform calibration adjustment if the Recorder fails any performance test in the verification procedure. Note Calibration should be performed under ambient temperature conditions between 20 °C and 30 °C. Calibration consists of four parts: I-Wave, I-Rogowski, V-Wave, and V-Impulse. Each part calibrates one measurement system in the Recorder. For each part, the calibration values are checked to be sure the Recorder is working correctly and calibration results are valid. All of the calibration steps for each of the four measurement systems must be completed before the calibration values can be written to the Recorder's nonvolatile memory. I-Wave, I-Rogowski, and V-Wave channels are calibrated using 55 Hz sine wave signals to minimize 50 Hz or 60 Hz power line interference with the calibration measurements. V-Impulse channels are calibrated using dc voltages, averaging calibration measurements to suppress power line interference. 14