Isotech has a wide range of Dry Blocks to suit probes requiring deeper immersion. This dry block temperature calibrator features large and deep calibration volumes. As such, it is less portable than earlier Dry Blocks, but has a higher capacity and retains outstanding temperature uniformity. This uniformity is so good that these larger products are also apparatus for Secondary Laboratories to realize the Fixed Points of ITS-90.

Medusa 510 dry block temperature calibrator has a maximum operating temperature of 550°C. The Medusa Model 511 can be used to 700°C, and features three-zone control. In addition to the main heating zone, there are additional top and bottom heaters, which compensate for the end losses, creating a constant temperature zone across the well.

For Comparison Calibration, the Medusa temperature calibrator should be used with an insert. The standard insert has six 8mm pockets, which are 250mm deep. Also available is an insert at 44mm diameter x 170mm deep, which is suspended from the top of the block so that the height is user-adjustable. For flexibility, the Medusa can also be used with accessories for infrared thermometers and surface sensors. The Medusa is available in two models, the BASIC (B) and the SITE (S). The B model includes a sophisticated temperature controller with a dual display for Set Temperature and Dry Block Temperature.

The S model includes a built-in digital thermometer to which an external standard thermometer can be connected, giving greater accuracy, eliminating temperature gradient and loading errors. Also included in the site model is a timer, which can set the bath between two temperatures, and automate ITS-90 fixed-point operation. For Surface Sensor and Black Body use, an external thermometer is recommended. For laboratory accuracy, the Medusa can be used with a high-end temperature indicator such as an Isotech TTI model.

This dry block temperature calibrator includes as standard: Windows Software, Computer Interface, and a Ramp to Set Point Feature. Increased resolution of ±0.01 available throughout the range via the PC interface, and from 0.01 to +99.99 locally on the auto-ranging front display. The controller features multi-point block-to-display correction, giving good absolute accuracy.

The S model has universal sensor input, allowing Platinum Resistance Thermometers, Thermocouples (types K, N, R, S, L, B, PL2, T, J, and E), along with Linear Process Inputs, including a 4-20mA current transmitters, to be displayed on the built-in indicator. This indicator can be programmed with up to five calibration points to provide high accuracy digital probe matching. The indicator and controller are both addressable over the communications link.