Go Direct Surface Temperature is designed for use in situations in which low thermal mass or flexibility is required. Special features include an exposed thermistor that results in an extremely rapid response time.
Typical uses for Go Direct Surface Temperature include the following:
- Skin temperature measurements
- Human respiration studies
- Specific heat experiments
- Heat transfer experiments
- Friction and energy studies
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.
Care and Maintenance
Go Direct Surface Temperature contains a small lithium-ion battery in the handle. The system is designed to consume very little power and not put heavy demands on the battery. Although the battery is warranted for one year, the expected battery life should be several years. Replacement batteries are available from Vernier (order code: GDX-BAT-300).
Storage and Maintenance
To store Go Direct Surface Temperature for extended periods of time, put the device in sleep mode by holding the button down for at least three seconds. The red LED will stop flashing to show that the unit is in sleep mode. Over several months, the battery will discharge but will not be damaged. After such storage, charge the device for a few hours, and the unit will be ready to go.
Exposing the battery to temperatures over 35°C (95°F) will reduce its lifespan. If possible, store the device in an area that is not exposed to temperature extremes.
The body of the Go Direct Surface Temperature Sensor is not water resistant and should never be immersed in water.
If water gets into the device, immediately power the unit down (press and hold the power button for more than three seconds). Disconnect the sensor and charging cable, and remove the battery. Allow the device to dry thoroughly before attempting to use the device again. Do not attempt to dry using an external heat source.
How the Sensor Works
This probe uses the 20 kΩ NTC Thermistor, which is a variable resistor. When the temperature increases, the resistance decreases non-linearly. The best-fit approximation to this nonlinear characteristic is the Steinhart-Hart equation. At 25°C, the resistance is approximately 4.3% per °C. The interface measures the resistance value, R, at a particular temperature and converts the resistance using the Steinhart-Hart equation:
T = [K0 + K1(ln 1000R) + K2(ln 1000R)3]-1 – 273.15
where T is temperature (°C), R is the measured resistance in kΩ, Ko =1.02119 × 10-3, K1 = 2.22468 × 10-4, and K2 = 1.33342 × 10-7. Our programs perform this conversion and provide readings in °C (or other units, if you load a different calibration).