- Other Fluke companies:
- Fluke
- Fluke Biomedical
- Fluke Networks
- Fluke Process Instruments
See more Fluke brands
Best performance thermometers in their price range
- Two Tweeners to choose from—reading PRTs or thermistors
- Best price/performance package
One of Fluke Calibration's best-selling products is the Tweener thermometer, and there’s a reason. No other company, not one, has a reference thermometer that comes close to the performance and features of the Tweener for anywhere near its price.
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.
Software
With our 9934 LogWare, both 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.
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 )
Specifications |
1502A | 1504 |
| Temperature Range† | −200 °C to 962 °C (−328 °F to 1764 °F) | Any thermistor range |
| Resistance Range | 0 Ω to 400 Ω, auto-ranging | 0 Ω to 1 MΩ, auto-ranging |
| Probe | Nominal RTPW: 10 Ω to 100 Ω RTD, PRT, or SPRT |
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 |
Steinhart-Hart thermistor polynomial Callendar-Van Dusen: R0, a, d, and b |
| Resistance Accuracy (ppm of reading) |
0 Ω to 20 Ω: 0.0005 Ω 20 Ω to 400 Ω: 25 ppm |
0 Ω to 5 KΩ: 0.5 Ω 5 KΩ to 200 KΩ: 100 ppm 200 KΩ to 1 MΩ: 300 ppm |
| Temperature Accuracy† | ±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 |
±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 KΩ 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 |
| Resistance Resolution | 0 Ω to 20 Ω: 0.0001 Ω 20 Ω to 400 Ω: 0.001 Ω |
0 Ω to 10 KΩ: 0.01 Ω 10 KΩ to 100 KΩ: 0.1 Ω 100 KΩ to 1 MΩ: 1 Ω |
| Temperature Resolution | 0.001 °C | 0.0001 °C |
| Excitation Current | 0.5 and 1 mA, user selectable, 2 Hz | 2 and 10 µA, 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, 1 A, nominal 230 VAC (±10 %), 50/60 Hz, 1 A, nominal, specify |
|
| Size (HxWxD) | 61 x 143 x 181mm (2.4 x 5.6 x 7.1 in) | |
| Weight | 1.0 kg (2.2 lb.) | |
| Probes from Fluke Calibration | 5615, 5627, 5626, 5628, 5622 | 5640-44, 5610-65 |
| Calibration | ISO 17025-accredited calibration provided | |
| †Temperature ranges and accuracy may be limited by the sensor you use. | ||
| Accessory | Description |
|---|---|
| 9301 |
Carrying Case, fits Tweener and 12 in probe |
| 2505 |
Spare Connector |
| 2508 |
Serial Cable Kit |
| 1929-2 |
System Verification, PRT with Readout, Accredited. |
| 1929-5 |
System Verification, Thermistor with Readout, Accredited. |
| 1930 |
System Calibration, PRT with Readout, Accredited. |
| 1935 |
System Calibration, Thermistor with Readout, NVLAP-accredited |
| Papers / Articles |
|---|
| Making the Right Choice for Your Temperature Readout |
PRT Temperature vs. Resistance Table (45.6 KB) |