12-Channel With Full Current Reversal

Using one of three automatic or user selectable currents, the PT12 repeatedly scans all 12 channels. Employing a full reversal current source, the PT12 eliminates polarity sensitive errors normally inherent to DC measuring techniques. Accuracy is further enhanced by referencing all measurements to high stability, temperature compensated internal refence resistors.

The supplied software allows each channel to be individually programmed with ITS-90 or Callendar-Van Dusen coefficients for direct conversion of resistance measurements to temperature. The PT12 connects to a PC over the RS-232 interface.

THERMOtelligent™ Smart 4-wire PRTs

An integrated microchip installed in the probe stores calibration coefficients and other information about the PRT. When the PRT is connected to the PT12, it automatically identifies itself and updates the PT12 with the calibration coefficients and other permanent information that is stored in the chip. Since the calibration coefficients are always kept in the THERMOtelligent™ PRT, the PRTs can be moved from channel to channel, or from one THERMOtelligent™-supported readout to another without requiring any reconfiguration.

The PT12 also works with any standard 4-wire 100 Ω or 25.5 Ω PRT. In the case of non-intelligent probes, coefficients may be easily entered by the operator through the touch screen. In addition, any 4-wire PRT can be converted to a THERMOtelligent™ Smart-PRT by RH Systems.

Thermal Control and Stability

The liquid jacketed chamber door uses heavy duty hinges, a recessed latching mechanism, a built-in light, and integrated heating for the door frame and window. The window inner pane is liquid jacketed and thermally controlled at the same temperature as the chamber to aid significantly in chamber stability and temperature uniformity. The chamber is also liquid jacketed meaning all 6 walls of the chamber are thermally controlled. An air-jacket is then encased within the liquid jacket to ensure unparalleled stability and uniformity.

Touch Screen Interface

The PT12 is equipped with a full color touch screen capable of data display in both numeric and graph formats. Graph positioning and scaling uses intuitive pinch/zoom gesturing.

Data Logging

Data may be logged automatically to a USB flash drive. If no drive is detected, data is logged to internal memory and may be copied to a USB drive when inserted at a later time.

Internal Reference Resistors

Measurements are compensated against drift using four high precision, high stability internal reference resistors. During each sampling sequence, the PT12 measures each reference resistor to define the measuring range and accurately determine the unknown values of each of the 12 channels. The result of this specific reference resistor measurement technique is a significant reduction in overall uncertainty.