Isotech milliK precision thermometer

The Isotech milliK Precision Thermometer sets a new benchmark for high‑accuracy temperature measurement across an exceptionally wide range from –270 °C to 1820 °C. Supporting SPRTs, PRTs, thermistors, thermocouples and 4–20 mA transmitters, the milliK provides a unified measurement platform for both industrial calibration and advanced metrology.

Versatile and highly accurate

With an accuracy of < ±5 ppm for PRTs, ±2 μV for thermocouples and ±1 μA for transmitters, the milliK delivers laboratory‑grade performance in a compact instrument. It supports multiple display units including °C, °F, K, Ohms, mV and mA, and offers both numerical and graphical display modes for intuitive operation.

Control of temperature sources

The milliK can directly control Isotech temperature sources, including dry blocks, liquid baths and furnaces. It can automatically step through a programmed sequence of temperature setpoints while logging all measurements to internal memory or a USB drive, enabling a fully automated calibration loop without the need for a PC. The instrument features two sensor channels and a third channel for current inputs. With the optional milliSKanner, the system can be expanded to 33 channels, each individually configurable for SPRT, PRT, thermistor or thermocouple inputs. This scalability makes the milliK suitable for both small laboratories and large‑scale calibration systems.

No‑compromise design

The milliK is entirely solid‑state, avoiding mechanical relays or switches that could reduce long‑term reliability. Fast current reversal eliminates thermal EMF errors in PRT measurements, while lead wire correction compensates for cable resistance. All inputs are galvanically isolated, including the 4–20 mA channel, preventing ground loops and improving noise immunity.

High‑resolution measurement

A display resolution of 0.0001 °C (0.1 mK) and a true measurement resolution of 0.00007 °C (0.07 mK) are achieved using a high‑performance Sigma‑Delta ADC. This level of precision is typically associated with thermometry bridges, making the milliK suitable for demanding applications such as fixed‑point calibration and stability studies.

The milliK can store more than six months of data in internal memory, and with a USB memory stick it can log continuously for years. Probe data and logged measurements can be exported at the touch of a button, and firmware updates are applied via USB. With USB host, Ethernet and dual RS232 interfaces, the milliK integrates seamlessly into modern laboratory environments. The milliK is designed for transparent and fully documented calibration. There are no internal adjustments; all calibration commands are issued via RS232 or the front panel. This ensures long‑term maintainability and independence from the manufacturer.

Reliability and industrial robustness

The instrument uses high‑quality connectors, including gold‑plated Lemo connectors for SPRTs and PRTs, and a rugged alumina thermocouple connector with integrated digital CJC sensing. The milliK is suitable for laboratory, production and field use, operating from both AC and DC power. The Isotech milliK combines the precision of a thermometry bridge with the versatility of a multi‑sensor calibrator. Its broad sensor compatibility, advanced measurement architecture, extensive logging capabilities and ability to control temperature sources make it a complete and future‑proof solution for modern temperature laboratories.