262 VT1422A Command Reference
Chapter 7
CALibration
CALibration
The Calibration subsystem provides for two major categories of calibration.
1. "A/D Calibration"— In these procedures, an external multimeter is used to
calibrate the A/D gain on all five of its ranges. The multimeter also determines
the value of the VT1422A's internal calibration resistor. The values generated
from this calibration are then stored in nonvolatile memory and become the
basis for "Working Calibrations. These procedures each require a sequence of
several commands from the CALibration subsystem (
CAL:CONFIG
…
,
CAL:VALUE
…
and
CAL:STORE ADC)
. Always execute *CAL? or a
CAL:TARE operation after A/D Calibration.
2. "Working Calibration"—Which has three levels (see Figure 7-3):
-- "A/D Zero"—This function quickly compensates for any short term A/D
converter offset drift. This would be called the auto-zero function in a
conventional voltmeter. In the VT1422A where channel scanning speed is of
primary importance, this function is performed only when the
CAL:ZERO?
command is executed. Execute CAL:ZERO? as often as the
control setup will allow.
-- "Channel Calibration"—This function corrects for offset and gain errors
for each module channel. The internal current sources are also calibrated.
This calibration function corrects for thermal offsets and component drift
for each channel out to the input side of the Signal Conditioning Plug-On
(SCP). All calibration sources are on-board and this function is invoked
using either the
*CAL?
or
CAL:SETup
command.
-- "Channel tare"—This function (
CAL:TARE
) corrects for voltage offsets in
external system wiring. Here, the user places a short across transducer
wiring and the voltage that the module measures is now considered the
new "zero" value for that channel. The new offset value can be stored in
non-volatile calibration memory (
CAL:STORE TARE
) but is in effect
whether stored or not. System offset constants which are considered
long-term should be stored. Offset constants which are measured relatively
often would not require non-volatile storage. CAL:TARE automatically
executes a *CAL?
-- "Remote Channel Calibration"—This function corrects for gain and offset
errors in each channel of a Remote Signal Conditioning unit (RSC).
Each RSC has its own calibration voltage source as well as shorting
switches. The calibration source is measured through dedicated analog
connections between the VT1539A SCP and the RSC. The source is then
used to stimulate the RSCs amplifiers to calibrate gain. The shorting
switches provide a zero volt source to calibrate offset.
Содержание VT1422A
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Страница 8: ...8 Notes...
Страница 22: ...22 Support...
Страница 57: ...Field Wiring 57 Chapter 2...
Страница 58: ...58 Field Wiring Chapter 2...
Страница 96: ...94 Programming the VT1422A VT1529A B for Remote Strain Measurement Chapter 3...
Страница 162: ...160 Programming the VT1422A for Data Acquisition and Control Chapter 4...
Страница 224: ...222 Creating and Running Algorithms Chapter 6...
Страница 419: ...VT1422A Command Reference 417 Chapter 7 Notes...
Страница 420: ...418 VT1422A Command Reference Chapter 7 Notes...
Страница 425: ...Specifications 423 Appendix A Thermocouple Type E 200 800 C SCPs VT1501 02 03A...
Страница 426: ...424 Specifications Appendix A Thermocouple Type E 200 800 C SCPs VT1508 09A...
Страница 427: ...Specifications 425 Appendix A Thermocouple Type E 0 800 C SCPs VT1501A 02A 03A...
Страница 428: ...426 Specifications Appendix A Thermocouple Type E 0 800 C SCPs VT1508A 09A...
Страница 429: ...Specifications 427 Appendix A Thermocouple Type E Extended SCPs VT1501A 02A 03A...
Страница 430: ...428 Specifications Appendix A Thermocouple Type E Extended SCPs VT1508A 09A...
Страница 431: ...Specifications 429 Appendix A Thermocouple Type J SCPs VT1501A 02A 03A...
Страница 432: ...430 Specifications Appendix A Thermocouple Type J SCPs VT1508A 09A...
Страница 433: ...Specifications 431 Appendix A Thermocouple Type K SCPs VT1501A 02A 03A...
Страница 434: ...432 Specifications Appendix A Thermocouple Type R SCPs VT1501A 02A 03A...
Страница 435: ...Specifications 433 Appendix A Thermocouple Type R SCPs VT1508A 09A...
Страница 436: ...434 Specifications Appendix A Thermocouple Type S SCPs VT1501A 02A 03A...
Страница 437: ...Specifications 435 Appendix A Thermocouple Type S SCPs VT1508A 09A...
Страница 438: ...436 Specifications Appendix A Thermocouple Type T SCPs VT1501A 02A 03A...
Страница 439: ...Specifications 437 Appendix A Thermocouple Type T SCPs VT1508A 09A...
Страница 440: ...438 Specifications Appendix A 5k Thermistor Reference SCPs VT1501A 02A 03A...
Страница 441: ...Specifications 439 Appendix A 5k Thermistor Reference SCPs VT1508A 09A...
Страница 442: ...440 Specifications Appendix A RTD Reference SCPs VT1501A 02A 03A...
Страница 443: ...Specifications 441 Appendix A RTD SCPs VT1501A 02A 03A...
Страница 444: ...442 Specifications Appendix A RTD SCPs VT1508A 09A...
Страница 445: ...Specifications 443 Appendix A 2250 Thermistor SCPs VT1501A 02A 03A...
Страница 446: ...444 Specifications Appendix A 2250 Thermistor SCPs VT1508A 09A...
Страница 447: ...Specifications 445 Appendix A 5k Thermistor SCPs VT1501A 02A 03A...
Страница 448: ...446 Specifications Appendix A 5k Thermistor SCPs VT1508A 09A...
Страница 449: ...Specifications 447 Appendix A 10k Thermistor SCPs VT1501A 02A 03A...
Страница 450: ...448 Specifications Appendix A 10k Thermistor SCPs VT1508A 09A...
Страница 454: ...452 Specifications Appendix A...
Страница 480: ...478 VT1529A B Verification Calibration Appendix C...
Страница 484: ...482 Glossary Appendix D Notes...