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Calibration of Laureate Meters, Counters & Timers

Analog Input Calibration

All ranges of Laureate analog signal conditioner boards and analog output boards are factory calibrated, with calibration factors stored in EEPROM on these boards. This allows different ranges to be selected via plug-in jumpers and different boards to be plugged into the meter, with no need to recalibrate the meter as a system. Calibration by Laurel uses CalWin custom software working with programmable Fluke 5500A calibrators. These are calibrated by Fluke annually and are self-calibrated weekly. The list of the equipment used to calibrate a specific Laureate meter or counter and the calibration dates of this equipment are available as an option by ordering a Certificate of Calibration.

Annual calibration of Laureate analog signal conditioner boards can be performed by a customer’s cal lab using an external standard, a PC, and Laurel’s Instrument Setup (IS) Software, which can be downloaded at no charge. For communications, the meter must be equipped with an RS232 board or USB board, and an appropriate PC communication cable. Following calibration, the communication board can be removed and be used to calibrate another Laureate meter. Laureate transmitters come standard with RS232/485 or Ethernet communications, as ordered.

Calibration of Laureate Meters, Counters and Timers
To use IS Software with a signal conditioner board, establish communications with the Laureate meter or transmitter. From the Main Menu:
  1. Press DPM => Get Setup to upload the meter’s setup to the PC.
  2. Press View => Setup to verify that the meter’s setup has been uploaded correctly.
  3. Press File =>Save Setup to save the setup information without calibration information as a disk file on the PC. Also write down the initial jumper positions. This will allow you to return your meter to the desired operating mode later after calibration has changed the meter setup.
  4. Press Calibration to open the calibration screen for the detected signal conditioner board, and follow the prompts. Shown below is the Calibration screen for the DC signal conditioner board, which can be used for DC, process, and strain gauge signals.
Calibration of Laureate Meters, Counters and Timers To calibrate, first select the Zero range, set jumpers to the signal conditioner board as shown for 0 Vdc, apply a short circuit to the input, and press Ready. Then select the other ranges to be calibrated, set jumpers for each range, apply the known full range signal, and press Ready. Press End to exit the calibration procedure when you have completed all ranges. IS Software will display “Calibration Complete”. Verify the jumper settings by referring to the latest meter or transmitter user manual.
After exciting the calibration procedure, reset jumpers and use IS Software to return your meter to the desired working setup. From the Main Menu, press File => Open Setup to retrieve your previously saved setup file, then press DPM => Put Setup to download that setup file back into your meter. Note that calibration data is not part of the setup file but is entered separately by the calibration procedure.

Counter/Timer Time Base Calibration

For frequency and rate measurements with the dual-channel signal conditioner board, or for rate measurements with the quadrature signal conditioner board, calibration is limited to making a correction in parts per million (PPM) to the quartz crystal oscillator on the microcomputer board. This correction is stored in EEPROM in the microcomputer board, so that signal conditioner boards can be changed with no need to recalibrate the counter.
For time base calibration, counter calibration may be performed in the field using the front panel push buttons:
  1. Write downthe counter’s initial jumper positions, operating mode, and scaling.
  2. Set jumpers for Logic level″ (top of page 14 of the counter user manual) to maximize the frequency range and remove filtering.
  3. Set InPut to rAtE and “A only”.
  4. Enter 0 in CALib to set the initial correction to 0 PPM.
  5. Set SCALE to -9.99999
  6. Set OFFSt1 to 999999
  7. Apply a 100.0000 kHz reference signal to channel A.
  8. Enter the displayed reading in CALib.
  9. Return the counter to its initial jumper positions, operating mode, and scaling.

Analog Output Calibration

Calibration Analog Output To verify calibration of the analog output board, select the Scale, Offset scaling method, set Scale to +00000, and set Offset to a desired number. The counter or transmitter reading will then be the same as Offset. Set Offset to +00000 for the Lo Range Reading and to +10000 for the Hi Range Reading. Use an external calibrated meter to verify that the desired analog outputs are achieved. The meter should have 5-digit accuracy, since the resolution of the analog output is 16 bits, or 0.0015% of full scale.
To calibrate the analog output board so that its full scale ranges are truly 0-20 mA, 0-10V, 4-20 mA or -10V to +10V, use Laurel’s CalWin30 calibration software in Manual mode.
  1. Establish serial communications between the meter and a PC COM port, which has to be COM1 or COM2.
  2. Press the AnaCal (analog output calibration) tab.
  3. In the resulting ANACAL screen, select Bipolar Output and Calibrate Mode.
  4. Press Re-Callibrate in the lower left of the screen. This will upload the board's current calibration.
  5. Connect the analog output to an external voltmeter.
  6. Press Volt Offset and enter the volts Reading in counts (0.00005V is 5 counts).
  7. Press Voltage Gain and enter the volts Reading in counts (9.9998V is 99998 counts).
  8. Connect the analog output to an external ammeter.
  9. Press Current Offset and enter the mA Reading in counts (0.00005 mA is 5 counts).
  10. Press Current Gain and enter the mA Reading in counts (19.997 mA is 19997 counts).
  11. Same steps for the -10V to +10V output range.
  12. Repeat each of the above steps for improved accuracy, referring to Previous for comparison.
  13. Press Accept to when you are done to save your calibration in the analog output board.
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