Isotech Primary SPRT 670 Family Thermometers

Isotech Primary SPRT 670 Family Thermometers

The 670SQ is the latest thermometer within the Isotech Primary SPRT 670 family. The design of this instrument is specially for optimum performance up to the aluminium tip. Its construction allows the four internal platinum electrode wires to expand and contract. This is the same way as silver-tip thermometers. The entire quartz construction of the supporting elements gives the most stable performance with minimal drift, and a unique platinum steel shield prevents heat build-up on the inside of the casing.

Due to the temperature range and design of this new device we can now offer 25.5 Ohm (Ro) and 100 Ohm (Ro). The construction, including the spiral sensor element, heat-shunt baffles and light scattering barriers, provides a thermometer with unsurpassed stability.

Temperature range

The 670SQ goes beyond the temperature range of the oxide growth to the level at which the oxide separates. The filling of the 670 consists of a unique argon/oxygen mixture. A 2.5 meter long, low thermal EMF, high temperature, shielded cable is connected in the handle. This is done via a voltage reducing transition in the fully pure platinum construction of the thermometer.

Gold-plated U-shaped clamps complete the cable construction and the 670SQ are also present in the elegant, softly padded case.  The 670SQ will be shipped after the stabilization process is complete. This is when the reproducibility of RTPW is within 0.0005°C after peaks to the extremes of its temperature range. The values of RTPW and Wga are standard.

Calibration Certificate

The 670SQ can only be certified with RTPW and Wga or with full UKAS calibration. You will receive an internationally Fixed Point calibration certificate. For best accuracy, the recommended maximum measurement currents are 1mA for 25.5Ω (Ro) and 0.5mA for 100Ω (Ro).

The 670SQ 650mm long is our recommended SPRT and offers ultra stability, with superior vibration, shock, immersion and automatic heating characteristics. From the success of the original Model 670 SPRTs, Isotech has introduced new models in the 670 series with a metal casing and low temperature models.