The TR-5i series is a line of compact waterproof data loggers manufactured by T and D Corporation. This line of devices was designed to measure and store temperature, voltage or pulse count. The units are water-resistant, and usable in an environment with temperature levels that range from -40°C to 80°C.
The unit is battery-operated, enabling utilization and placement anywhere, without the need of AC power. It is equipped with a thermistor with approximately 35 minutes response time. Logging capacity of this device can reach up to 16,000 readings.