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Thermometer Readouts for RTD, PRT, and Thermistor Sensors

 

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Features

Three Tweeners to choose from

Battery packs available

Best price/performance package

Use our Feedback Form for more information, to request a catalog or for a Price Quote

Specifications

1502A

1503

1504

Temperature Range†

–200°C to 962°C (–328°F to 1764°F)

–200°C to 1200°C (–328°F to 2192°F)

Any thermistor range

Resistance Range

0W to 400W, auto-ranging

0W to 25W, auto-ranging

0W to 1 MW, auto-ranging

Probe

Nominal RTPW: 25W to 100W
RTD, PRT, or SPRT

Nominal RTPW: 0.25W, 2.5W, 3W, and 5W PRT

Thermistors

Characterizations

ITS-90 subranges 4, 6, 7, 8, 9, 10, and 11
IPTS-68: R0, a, d, a4, and c4
Callendar-Van Dusen: R0, a, d, and b

ITS-90 subranges 6, 7, and 8
HTPRT 7th-order polynomial reference function with optional 2nd-order deviation function
Callendar-Van Dusen: R0, a, and d

Steinhart-Hart thermistor polynomial
Callendar-Van Dusen: R0, a, d, and b

Resistance Accuracy
(ppm of reading)

0W to 20W: 0.0005W
20W to 400W: 25 ppm

0W to 2.5W: 0.0002W
2.5W to 25W: 80 ppm

0W to 5 KW: 0.5W
5 KW to 200 KW: 100 ppm
200 KW to 1 MW: 300 ppm

Temperature Accuracy†, typical  (meter only)

±0.004°C at –100°C
±0.006°C at 0°C
±0.009°C at 100°C
±0.012°C at 200°C
±0.018°C at 400°C
±0.024°C at 600°C

2.5W–5W nominal RTPW
–200°C to 100°C: ±0.02°C
100°C to 400°C: ±0.05°C
400°C to 800°C: ±0.1°C
800°C to 1000°C: ±0.125°C
1000°C to 1200°C: ±0.15°C

0.25W nominal RTPW
0°C to 500°C: ±0.25°C
500°C to 1200°C: ±0.3°C

±0.002°C at 0°C
±0.002°C at 25°C
±0.004°C at 50°C
±0.010°C at 75°C
±0.020°C at 100°C
(Using 10 KW thermistor sensor, a=0.04. Does not include probe uncertainty or characterization errors.)

Operating Temperature Range

16°C to 30°C

13°C to 33°C

13°C to 33°C

Resistance Resolution

0W to 20W: 0.0001W
20W to 400W: 0.001W

0W to 10W: 0.00001W
10W to 25W: 0.0001W

0W to 10 KW: 0.01W
10 KW to 100 KW: 0.1W
100 KW to 1 MW: 1W

Temperature Resolution

0.001°C

0.01°C

0.0001°C

Excitation Current

0.5 and 1 mA, user selectable, 2 Hz

3 and 5 mA, user selectable

2 and 10 mA, automatically selected

Measurement Period

1 second

Digital Filter

Exponential, 0 to 60 seconds time constant (user selectable)

Probe Connection

4-wire with shield, 5-pin DIN connector

Communications

RS-232 serial standard
IEEE-488 (GPIB) optional

Display

8-digit, 7-segment, yellow-green LED; 0.5-inch-high characters

Power

115 VAC (±10%), 50/60 Hz, 10 A, nominal
230 VAC (±10%), 50/60 Hz, 10 A, nominal, specify

Size

5.6" W x 7.1" D x 2.4" H (143 x 181 x 61 mm)

Weight

2.2 lb. (1.0 kg)

Probes from Hart

5612, 5613, 5614, 5627, 5626, 5628, 5622

5640-44, 5610-65

†Temperature ranges and accuracy may be limited by the sensor you use.

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 (the Model 1504 is even more accurate, up to ±0.003°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.

Want more? There are two more Tweeners for specific applications, including the Model 1503 High Temperature PRT Readout and the Model 1504 Thermistor Readout.

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Model 1503 High Temperature PRT Readout

The Model 1503 Tweener reads low-resistance, high-temp PRT probes used for temperatures above the aluminum point up to 1200°C. It is absolutely the only readout at this price that reads low-resistance, high-temp probes. It reads 0.25-ohm, 2.5-ohm, 3-ohm, and 5-ohm probes. Its general accuracy is ±0.02°C and typically ±0.15°C at 1200°C. It uses the ITS-90 subranges or a 7th-order polynomial for HTPRTs.

Model 1504 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.

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 Calibrate-it 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 )

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Use our Feedback Form for more information, to request a catalog or for a Price Quote