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National Instruments Corporation

3

NI 6711/6713/6731/6733 Calibration Procedure

Equipment and Other Test Requirements

This section describes the equipment, test conditions, documentation,
and software you need to calibrate the NI 6711/6713/6731/6733.

Test Equipment

To calibrate the NI 6711/6713/6731/6733, you need a high-precision
DMM that is at least 10 ppm (0.001%) accurate. NI recommends that you
use the Agilent 3458A DMM for calibration.

If you do not have an Agilent 3458A DMM, use the accuracy specifications
to select a substitute calibration standard.

If you do not have custom connection hardware, you may need a connector
block such as the NI CB-68 and a cable such as the SH6868-D1. These
components give you easy access to the individual pins on the 68-pin
I/O connector.

Test Conditions

Follow these guidelines to optimize connections and test conditions during
calibration:

Keep connections to the NI 6711/6713/6731/6733 short. Long cables
and wires act as antennae, picking up extra noise, which can affect
measurements.

Use shielded copper wire for all cable connections to the device.

Use twisted-pair wire to eliminate noise and thermal offsets.

Maintain a temperature between 18 and 28 °C. To operate the module
at a specific temperature outside this range, calibrate the device at that
temperature.

Keep relative humidity below 80%.

Allow a warm-up time of at least 15 minutes to ensure that the
measurement circuitry is at a stable operating temperature.

Software

Because the NI 6711/6713/6731/6733 is a PC-based measurement device,
you must have the proper device driver installed in the calibration system
before attempting calibration. For this calibration procedure, you need
NI-DAQ version 6.9.2 or earlier installed on the calibration computer.
NI-DAQ, which configures and controls the NI 6711/6713/6731/6733,
is available at

ni.com/downloads

.

Содержание NI 6711

Страница 1: ...red for calibrating NI 6711 6713 6731 6733 devices Note Refer to ni com support calibrat mancal htm for a copy of the ni671xCal dll file What Is Calibration Calibration consists of verifying the measurement accuracy of a device and adjusting for any measurement error Verification is measuring the performance of the device and comparing these measurements to the factory specifications During calibr...

Страница 2: ...een calibrated with respect to an external standard However external variables such as temperature can still affect measurements The new calibration constants are defined with respect to the calibration constants created during an external calibration ensuring that the measurements can be traced back to the external standards In essence internal calibration is similar to the auto zero function fou...

Страница 3: ...timize connections and test conditions during calibration Keep connections to the NI 6711 6713 6731 6733 short Long cables and wires act as antennae picking up extra noise which can affect measurements Use shielded copper wire for all cable connections to the device Use twisted pair wire to eliminate noise and thermal offsets Maintain a temperature between 18 and 28 C To operate the module at a sp...

Страница 4: ...ow to configure the device in NI DAQ Refer to the NI 671X 673X User Manual for detailed installation instructions You can install this manual when you install NI DAQ 1 Power down the computer 2 Install the NI 6711 6713 6731 6733 in an available slot 3 Power on the computer 4 Launch Measurement Automation Explorer MAX 5 Configure the NI 6711 6713 6731 6733 device number 6 Click Test Resources to en...

Страница 5: ...I DAQ User Manual for PC Compatibles at ni com manuals These two documents provide detailed information about using NI DAQ The function reference help includes information on the functions in NI DAQ The user manual provides instructions on installing and configuring DAQ devices and detailed information on creating applications that use NI DAQ These documents are the primary references for writing ...

Страница 6: ... those specified by the calibration procedure 2 To internally calibrate the device call the Calibrate_E_Series function with the following parameters set as indicated calOP set to ND_SELF_CALIBRATE setOfCalConst set to ND_USER_EEPROM_AREA calRefVolts set to 0 3 Connect the DMM to DAC0OUT as shown in Table 1 4 Refer to the table from the Specifications section that corresponds to the device you are...

Страница 7: ...rifying the Performance of the Counter This procedure verifies the performance of the counter The NI 6711 6713 6731 6733 devices have only one timebase to verify so you only need to verify counter 0 Because you cannot adjust this timebase you can only verify the performance of counter 0 Make sure that you have read the Equipment and Other Test Requirements section and then follow this procedure 1 ...

Страница 8: ...annot modify these values which provides a level of security that ensures users do not accidentally access or modify any calibration constants adjusted by the metrology laboratory This step in the calibration process calls functions in NI DAQ and in the ni671x dll For further information on the functions in the ni671x dll refer to the comments in the ni671x h file 1 Disconnect all cables to the de...

Страница 9: ...rom the device The device is now adjusted with respect to the external source After the device is adjusted you can verify the AO operation by repeating the Verifying Analog Output section Specifications The following tables are accuracy specifications to use when verifying and adjusting the NI 6711 6713 6731 6733 The tables show the specifications for 1 year and 24 hour calibration intervals Using...

Страница 10: ...ar the test point value should fall between the upper and lower limit values These limits are expressed in volts Counters Because you cannot adjust the resolution of the counter timers these values do not have a 1 year or 24 hour calibration period However the test point and upper and lower limits are provided for verification purposes Table 3 Analog Output for the NI 6711 6713 Range V Polarity Te...

Страница 11: ... Programs National Instruments NI DAQ NI DAQ Help and the NI DAQ User Manual for PC Compatibles at ni com manuals for additional information on the software structure Verifying Analog Output Figure 1 Verifying Analog Output Table 5 Counter Set Point MHz Upper Limit MHz Lower Limit MHz 5 4 9995 5 0005 From the specification table for the product determine the channel and voltage to verify AO_Config...

Страница 12: ...PCTR_Control deviceNumber 0 ND_RESET GPCTR_Set_Application deviceNumber 0 ND_PULSE_TRAIN_GNR GPCTR_Change_Parameter deviceNumber 0 ND_COUNT_1 2 GPCTR_Change_Parameter deviceNumber 0 ND_COUNT_2 2 Select_Signal deviceNumber ND_GPCTR0_OUTPUT ND_GPCTR0_OUTPUT ND_LOW_TO_HIGH GPCTR_Control deviceNumber 0 ND_PROGRAM ...

Страница 13: ...Adjusting the NI 6711 6713 6731 6733 Figure 3 Adjusting the NI 6711 6713 6731 6733 Calibrate_E_Series deviceNumber ND_SELF_CALIBRATE ND_USER_EEPROM_AREA 0 Get_Cal_Date deviceNumber CalDate Calibrate_E_Series deviceNumber ND_EXTERNAL_CALIBRATE ND_USER_AREA 5 0 Copy_Const deviceNumber ...

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