The Thermal Vial™ is a temperature sensing system designed for ultralow freezer, cryogenic storage, blood bank, and other medical and scientific storage applications to –269°C. The system includes an RTD probe, match calibrated 4-20 mA transmitter in a moistureproof enclosure, and a fluid-filled container that lets the sensor mimic the thermal response of other freezer contents. According to the manufacturer, the Thermal Vial container acts as a thermal ballast to delay reaction and provides a repeatable time response.

—Minco Products, Inc.

Minneapolis