Apogee designs temperature sensors for monitoring in many environments, many of which present unique challenges to accuracy.
To meet these challenges, they offer three styles of thermistors and the most accurate PRT commercially available.
ST-100 Thermistor Temperature Sensor
The ST-100 temperature sensor consists of a precision thermistor enclosed in a waterproof rubber covering, a precision bridge resistor, and lead wires to connect the sensor to a measurement device.
Temperature Measurement Range: -50 to +70 C
Accuracy: 0.1 C above 0 C
Rugged - designed for continuous temperature measurement in air, soil, or water.
ST-200 Fine-Wire Thermistor
The ST-200 temperature sensors have a fine-wire precision thermistor, precision bridge resistor, and lead wires. Sensors are weather resistant and are designed for temperature measurement of delicate surfaces (e.g., leaves, fruits) and small samples (where a narrow field of view infrared radiometer may not be suitable due to integration over the conical field of view).
Temperature Measurement Range: -50 to +70 C
Accuracy of 0.2 C above 0 C
Rapid Response - Small size provides a more rapid response to changes in temperature than larger sensors.
Remarkably Rugged - Can be repeatedly pushed into plant tissues with tweezers. Wires are flexible making the sensor less sensitive to breakage than similarly-sized fine wire thermocouples.
ST-110 Thermistor
ST-110 temperature sensors consist of a precision thermistor, a precision bridge resistor, and lead wires to connect the sensor to a measurement device. The ST-110 is designed for continuous air temperature measurement when housed in the TS-100 aspirated radiation shield.
Temperature Measurement Range: -50 to +70 C
Accuracy of 0.1 C above 0 C
Weatherproof - Sensor is weatherproof and has excellent long-term stability.
Reduced Solar Loading - Reflective white heat-shrink reduces solar loading on the cable behind the thermistor.
Minimal Thermal Conduction - Constantan wire transition is used to minimize thermal conduction to the sensor tip.
ST-300 Platinum Resistance Thermometer (PRT)
The ST-300 is a 1/10 DIN platinum resistance thermometer (PRT), consisting of a platinum resistive element enclosed in a stainless steel sheath, and lead wires to connect the sensor to a measurement device.
Temperature Measurement Range: -50 to +70 C
Accuracy of 0.1 C
Weatherproof - ST-300 sensors are weatherproof and designed for continuous air temperature measurement when housed in an aspirated radiation shield, such as the TS-100 fan aspirated radiation shield.
