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Tuesday, June 21, 2016

FLUKE Thermometer 51 - 52 - 53 - 54 Series II - performance test - Hyper terminal – Calibration – Testing equipment repair and service

Category: Testing Equipment Repair and Service 

Contents of this article 

  • Performance Test 
  • Calibration procedure  
  • Hyper terminal 


FLUKE 51-52-53-54 Series II

Performance Tests
Performance tests are recommended for incoming inspection, periodic maintenance, and for checking the thermometer’s specifications. If the thermometer fails any part of the performance tests, calibration and/or repair is indicated.
Before performing these tests:
1. Allow the thermometer to stabilize to room temperature, +23 oC ± 5 oC (+73 oF ± 9 oF).
2. Check the batteries and replace them if necessary.
Display Test
Turn the thermometer on while pressing the h button. All display segments are displayed until the h button is released. Confirm that all the display segments
Keypad Test
Check that all keypad switches are functional by pressing each key and confirming the proper response on the display.
Wide Range Performance Test Procedure
This test verifies the instrument specifications. If the instrument fails this test, perform the calibration procedure. If the unit continues to fail, it should be taken to a Fluke service center.
Ice Bath Construction
To begin the performance test, first construct an ice bath as follows:
1. Prepare a Dewar Flask by drilling two holes in its cap to accept the Mercury thermometer and thermocouple wires, or use a standard laboratory cork.
2. Fill the Dewar Flask with shaved or crushed ice made from distilled water.
3. Fill the Dewar Flask with enough distilled water so that the ice turns to slush, but do not add enough water to float the ice.
Note
As the ice melts, siphon off the excess water and add more ice. Allow approximately 5 to 10 minutes for the water to drop back to the freezing point.
4. Replace the Dewar Flask cap or cork, and insert the thermocouple wires and Mercury thermometer as shown in Figure 2. Insert the Mercury thermometer to the same depth as the thermocouple wire

Ice Bath Test
Use the following procedure to test the thermometer. If the thermometer has two inputs, this test should be conducted on both thermocouple inputs.
1. If not already selected, select K-type thermocouple on the thermometer using the
SETUP, UP, DOWN, and ENTER buttons.
2. Connect the equipment as shown in Figure above . Allow the setup to thermally stabilize at least 5 minutes after inserting the thermocouple into the thermometer.
3. Verify that the ice bath temperature reads 0.0 oC ± 0.06 oC on the Mercury thermometer.
4. Short (or apply 0 mV) to the copper wires at the Calibrator.
5. Verify the thermometer reads 0.0 oC ± 0.3 oC.
6. If this test fails, reposition the thermocouple wires and Mercury thermometer to the same depth in the ice bath, and repeat steps 3-5. If the test continues to fail, perform the calibration procedure, located after this procedure.
7. Remove the short applied in step 4.
8. Using Table 3, steps 2-5, obtain an output from the Calibrator equal to the values in the “Input Voltage (mV DC)” column, and verify the thermometer reads within the limits specified. If any step fails, perform the calibration procedure located later in this section.
9. Disconnect the thermocouple from the input terminals. This completes the ice bath test.
Verification of IR Communications Port (Fluke 53 and 54)
This section explains how to verify the operation of the IR Communications Port (IR port). Perform the following procedure using a PC and HyperTerminal. The IR port can also be verified using Flukeview software. To set up a HyperTerminal file, follow these steps:
1. Connect the IR adapter cable to the DB9 Adapter connector. Connect the other end of the DB9 Adapter to a COM port of the PC.
2. Place the Fluke 53 or 54 in front of the IR adapter.
3. Open up a HyperTerminal session. Select Start button, Programs, Accessories,
HyperTerminal.
4. Open up a New Connection with a name like “Fluke 54 IR Test”.
5. When the Connect To box appears, select the COM1 or COM2 (the port that the IR adapter cable is plugged into).
6. Select Port Settings: 9600 baud rate, 8 data bits, no parity, 1 stop bit, and no flow control.
7. Under File, select properties. Verify that the correct port is selected. Click on Configure. Verify that port settings are correct (the baud rate may need to be changed to 9600).
8. Select the Settings tab then click on ASCII Setup. Check the following boxes:
# Echo typed characters locally
# Append line feeds to incoming line ends
# Wrap lines that exceed terminal width
To open a HyperTerminal file to test the IR port, use the following procedure:
1. Under File, select Save As. Use a file name such as “Fluke 54 IR Test” and then click on save.
2. Click on the phone disconnect icon.
3. Click on open folder or under File select Open. Double click on Fluke 54 IR Test.
4. Type in "ID" followed by the Enter key (notice the "ID" is capitalized).
5. The display of the thermometer now shows the thermometer name (Fluke 53-II or Fluke 54-II), and the units operating software version (e.g. Fluke 54-II, V1.01).
Calibration and Offset Adjustment
Calibration consists of two parts:
1. Calibration of the A/D converter, using the set up shown in Figure 3.
2. Reference junction calibration, using the ice bath test set up shown in Figure 2.
A/D Calibration
To calibrate the A/D portion of the thermometer, follow these steps:
1. Connect the calibrator to the T1 input of the thermometer using copper (nonthermocouple) wire and a copper thermocouple connector. Refer to Figure  for proper equipment connections.
2. Turn the thermometer on, with a small, blunt probe, press the calibration button located on the back and in the center of the thermometer.


3. The menu on the display changes to “CAL A-d”.
Note
Within CAL are four menu options that may be accessed by pressing E:
# CAL A-d prompts the operator for the A/D calibration inputs in mV dc.
# CAL rEF allows the operator to calibrate the reference junction at a known temperature.
CAL donE saves the new calibration constants in memory.
# CAL Abrt ignores calibration changes (turning the thermometer off while in CAL will also ignore calibration changes).
4. Press UP or DOWN to select different menu options.
5. With CAL A-d selected, press ENTER. The thermometer prompts “80”. Set the calibrator to +80.000 mV and allow the output to stabilize.
Note
For steps 6 and 8, keep hand and body motion to a minimum while the thermometer takes A/D readings.
6. Press E. Wait while it takes A/D readings.
7. When the thermometer prompts for “-8”, set the Calibrator to -8.0000 mV. Allow the output to stabilize.
8. Press ENTER on the thermometer and wait while it takes A/D readings. The thermometer now shows the measured value in the bottom portion of the display. Millivolts appears on the left side and microvolts appears on the right side.
9. If the measurement is from –7 995.0 to –8 005.0, press ENTER and the meter will return to the calibration menu and display CAL rEF. If the measurement is outside – 7995.0 to –8005.0, press ENTER once to return to the calibration menu. Using UP or DOWN, select CAL A-d and try the A/D calibration procedure a second time starting at step 5.
10. Using UP or DOWN, select “CAL donE”, then press E to store the calibration in memory.
11. To ignore the calibration changes, use UP or DOWN, and select “CAL Abrt” and press ENTER.
12. Proceed to Reference Junction Calibration.
Using the Offset to Adjust for Variation Between Thermocouples
Use the offset option in the thermometer SETUP mode to adjust the thermometer's readings for errors of a specific thermocouple. Use the following procedure:
1. Plug the thermocouple into the thermometer input then allow the setup to thermally stabilize at least 5 minutes.
2. Place the thermocouple in a known, stable temperature environment (such as an ice bath, lag bath, or a dry well calibrator).
3. Allow the readings to stabilize.
4. In SETUP, change the offset until the primary display reading matches the bath temperature

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