One of Hart’s best-selling products is the Tweener thermometer, and there’s a reason. No other company, not one, has a thermometer that comes close to the performance and features of the Tweener for anywhere near its price.

Model 1502A PRT Readout
The Model 1502A Tweener features accuracy up to ±0.006°C. In addition, it reads both 100-ohm and 25-ohm probes, has a resolution of 0.001°C across its entire range and is the smallest unit in the industry. It also has an optional battery pack for completely portable operation.

Each Tweener is programmable to match any 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 its firmware. If your probe has been calibrated for any of the subranges of the ITS-90, you simply enter the coefficients directly into the 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.

Software
With our Model 9934 LogWare, all three Tweener models may be used for real-time data acquisition. Collect data and analyze it graphically or statistically. Additionally, Tweeners may be used as reference thermometers with our MET/TEMP II software.

Battery Option
If you want freedom from AC power in the field or on the plant floor, order Model 2502 and we’ll install a DC power board in your Tweener. Then you can connect your own 12-volt DC power or order Hart’s 9313 Battery Pack. Our battery gives you three to eight hours between charges. It includes a charger and a nylon pouch with a belt clip.

Calibration Choices
Each Tweener and its accompanying probe (sold separately) have their own individual calibration reports. Overall system error can be calculated from the individual errors, rendering the added cost of system data unnecessary. However, for those requiring it, system data is available at two or more temperatures of your choice. (See Calibration Model 1929-X )