Performance Testing and Calibration

4

Performance Tests

4-9. Open Thermocouple Response Test

Use the following procedure to test the open thermocouple response:

1.Switch OFF power to the instrument and disconnect all high voltage inputs.

2.Remove the Input Module from the rear of the instrument. Open the Input Module and connect test leads to the H (high) and L (low) terminals of channel 1. Reinstall the Input Module into the instrument.

3.Reconnect power and switch the instrument ON.

4.Connect the test leads from the Input Module to an 820 ohm resistor.

5.Select the temperature function and K thermocouple type for channel 1. Then press MON.

6.The value displayed should approximate the ambient temperature.

7.Replace the 820-ohm resistor with a 4-kilohm resistor to simulate a high resistance or open thermocouple.

8.Verify a reading of "otc".

9.The Open Thermocouple Response Test is complete. However if you desire to perform this test on any other Input Module channel (2 through 20) repeat steps 1 through 8, substituting the appropriate channel number.

4-10. RTD Temperature Accuracy Test

The following two RTD Temperature Accuracy Tests are different in that one uses a Decade Resistance Source and the other uses an RTD. Only one of the tests needs to be performed to verify operation.

4-11. RTD Temperature Accuracy Test (Using Decade Resistance Source).

Verify that the channel 0 accuracy verification tests for dc volts and 300-ohm range meet minimum acceptable levels.

1.Switch OFF power to the instrument and disconnect all high voltage inputs.

2.Remove the Input Module from the rear of the instrument. Open the Input Module and connect a pair of test leads (keep as short as possible) to the H (high) and L (low) terminals of channel 1. For 4-terminal performance testing, connect a second pair of test leads to the H (high) and L (low) terminals of channel 11. Reinstall the Input Module into the instrument.

3.Connect the channel 1 test leads to the Output HI and LO terminals on the Decade Resistance Source. For 4-terminal performance testing, also connect channel 11’s test leads to the Output HI and LO terminals of the Decade Resistance Source.

Connect as shown in Figures 4-1 and 4-2.

Note

4-terminal connections are made using pairs of channels. 4-terminal measurements can only be made on channels 1 through 10. The accompanying pairs are channels 11 through 20.

4.Switch the instrument ON.

5.Select the 4-terminal RTD temperature function, RTD type PT, for channel 1 on Hydra.

6.Press MON. For each resistance, ensure that the display reads within the range shown in Table 4-5.

4-11

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Fluke 2625A, 2635A service manual Open Thermocouple Response Test, RTD Temperature Accuracy Test
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2635A, 2625A specifications

The Fluke 2625A is a sophisticated data logger designed for a wide range of industrial and laboratory applications. This versatile instrument excels in capturing and monitoring temperature and voltage measurements with precision and reliability. One of its standout features is its ability to record data from various sensors, making it ideal for environments where comprehensive data acquisition is critical.

Equipped with a large LCD display, the Fluke 2625A provides clear and user-friendly access to real-time measurement data. Its graphical interface allows users to visualize trends and monitor readings easily, which significantly enhances usability. The device supports a variety of input types and can connect to thermocouples, RTDs, and other sensors, offering great flexibility for various measurement tasks.

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In summary, the Fluke 2625A is a powerful data logger that combines versatility, accuracy, and reliability. Its user-friendly interface, advanced measurement technologies, and robust design make it an essential tool for professionals in various industries, from manufacturing and HVAC to research and development. Whether monitoring temperature changes in a laboratory or assessing voltage levels in an industrial setting, the Fluke 2625A stands out as a trusted solution for effective data logging and analysis.
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