Tweener Thermometer Readouts
1502A Tweener PRT Readout
The Fluke 1502A Tweener (formerly Hart Scientific) features accuracy up to ?0.006 ?C (the 1504 is even more accurate, up to ?0.002 ?C). In addition, it reads 100-ohm, 25-ohm, and 10-ohm probes, has a resolution of 0.001 ?C across its entire range, and is the smallest unit in its class.
Each Tweener is programmable to match a probe?s constants for maximum linearity and accuracy. All probe constants and coefficients are programmed through simple, front-panel keystrokes. Temperature is displayed in ?C, ?F, K, or resistance in ohms.
The 1502A accurately measures the resistance of the probe and then converts the resistance to a temperature value using its built-in algorithms.
For convenience, the 1502A reads the common industrial grade IEC-751 or ?385 ALPHA RTD without any programming. Enter the actual R0 and ALPHA of the individual probe for increased accuracy. For maximum accuracy, use the ITS-90 formulas. The Tweener accepts the subranges 4 and 6 through 11.
ITS-90 formulas reside in the Tweener?s firmware. If your probe has been calibrated for any of the above subranges of the ITS-90, you simply enter the coefficients directly into your Tweener.
Each thermometer comes complete with an RS-232 interface for automation of temperature data collection, calibrations, or process control functions. An IEEE-488 interface is available as an option.
The 1502A is calibrated digitally using the front-panel buttons. You never have to open the box to calibrate it. This calibration protocol further reduces the cost of the 1502A. It goes where you go and works the way you want it to.
1504 Tweener Thermistor Readout
If you need more accuracy in a limited temperature range, the Model 1504 Tweener gives it to you as a thermistor readout. Thermistors are less fragile than PRTs and less likely to be impacted by mechanical shock. Thermistors are more sensitive to temperature, have faster response times, and come in many shapes for different applications.
Typical accuracy of a 1504 is ?0.002 ?C with a resolution of 0.0001 ?C.