Vernier Software and Technology
Vernier Software & Technology

Thermocouple User Manual

Thermocouple

The Thermocouple is a simple and rugged sensor designed to measure temperature in the range of –200°C to 1400°C. This sensor could be used for any of the following experiments:

  • Study how the temperature inside a Bunsen burner flame varies with position.
  • Compare the temperatures of different flames (candles vs. Bunsen burner).
  • Check the calibration of ovens.
  • Experimentally determine the melting point of copper, bismuth, or other solids.
  • Measure the temperature of dry ice or liquid air.

Note: Vernier products are designed for educational use. Our products are not designed nor are they recommended for any industrial, medical, or commercial process such as life support, patient diagnosis, control of a manufacturing process, or industrial testing of any kind.

What's Included

  • Thermocouple

Compatible Software and Interfaces

The Thermocouple may require a compatible interface and software. Choose a platform below to see compatible interface and software options.

Getting Started

  1. Connect the sensor to the interface (LabQuest Mini, LabQuest 2, etc.).
  2. Start the appropriate data-collection software (Logger Pro, Logger Lite, LabQuest App) if not already running, and choose New from File menu.

The software will identify the sensor and load a default data-collection setup. You are now ready to continue your experiment.

If you are collecting data using a Chromebook™, mobile device such as iPad® or Android™ tablet, or a Vernier wireless sensor or interface, please see the following link for up-to-date connection information:

www.vernier.com/start/tca-bta

Using the Product

Connect the sensor following the steps in the Getting Started section of this user manual.

The thermocouple wire is insulated by a high-temperature glass that has a lower maximum temperature (704°C, 1300°F) than the wire itself (1400°C, 2552°F). Therefore, in use, place only the tip of the wire in the heat source and keep the insulation out of direct contact with the heat source.

The default data-collection range for the Thermocouple is set to have the best accuracy between 0°C and 900°C. There are two other settings available for data collection if you would like increased accuracy at a lower temperature or a higher temperature.

  • The low setting has the best accuracy for temperatures between –200°C and 0°C.
  • The high setting has the best accuracy for temperatures between 900°C and 1400°C.

To access these different ranges in Logger Pro or Logger Lite:

  1. From the Experiment menu, select Set Up Sensors.
  2. Select your interface. This will open a new dialog box.
  3. Click on the sensor icon button to display the drop down menu and select the temperature setting you would like to use.

For information on accessing the other temperature settings on a different platform, see www.vernier.com/til/1440

Videos

Calibration

You should not have to perform a new calibration when using the Thermocouple in the classroom. The sensor is custom calibrated before it is shipped. If you wish to calibrate the sensor, you must conduct a three-point calibration using Logger Pro or Logger Lite. If you choose to store this calibration to the sensor, you will have to overwrite either the high or the low factory-installed calibrations.

Specifications

Typical accuracy

  • 0°C to 900°C: ±3°C
  • –200°C to 0°C: ±5°C
  • 900°C to 1400°C: ±15°C

12-bit resolution

0.40°C

Power

11 mA @ 5 VDC

Calibration equations

  • Equation: 2nd Order Polynomial
  • y = cx^2 + bx + a
 
  • 0°C to 900°C: a: –185.19, b: 311.32, c: –1.7873
  • –200°C to 0°C: a: –274.27, b: 640.14, c: –305.66
  • 900°C to 1400°C: a: –7.7423, b: 195.71, c: 16.904

How the Sensor Works

Thermocouples make use of a property that occurs when two wires composed of dissimilar metals are joined at both ends. When one of the joined ends is heated, a continuous current is created and flows in a thermoelectric circuit. The small open‑circuit voltage of this circuit (known as the Seebeck voltage) is a function of the junction temperature and the composition of the two metals. (The Vernier Thermocouple uses a type-K thermocouple wire.) By measuring the voltage, the temperature at the joined end can be calculated.

Measuring the Seebeck voltage requires connecting a voltmeter’s leads to the thermocouple wires. This new junction creates an additional thermocouple. In order to compensate for this new thermocouple, we use a method called cold‑junction compensation. This method requires knowing the temperature at the new junction. Traditionally, these junctions were held at 0°C in an ice bath. The Vernier Thermocouple performs a direct measurement of the temperature of the reference junction with an integrated-circuit amplifier.

Repair Information

If you have watched the related product video(s), followed the troubleshooting steps, and are still having trouble with your Thermocouple, contact Vernier Technical Support at support@vernier.com or call 888-837-6437. Support specialists will work with you to determine if the unit needs to be sent in for repair. At that time, a Return Merchandise Authorization (RMA) number will be issued and instructions will be communicated on how to return the unit for repair.

Warranty

Vernier warrants this product to be free from defects in materials and workmanship for a period of five years from the date of shipment to the customer. This warranty does not cover damage to the product caused by abuse or improper use. This warranty covers educational institutions only.

Contact Support

Fill out our online support form or call us toll-free at 1-888-837-6437.

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