Probe thermometer 150 series

Pt100thermistorRTD

Key features

• 1502A: accuracy up to ±0.006 °C; range −200 °C to 962 °C; resolution 0.001 °C.
• 1504: accuracy up to ±0.002 °C; thermistor measurement; resolution 0.0001 °C.
• Measurement rate up to 2 readings per second (typical period 1 s).
• RS-232 standard; optional IEEE-488 (GPIB); compatible with LogWare 9934 and MET/TEMP II.
• ISO 17025-accredited calibration available.

Product overview
Fluke Calibration 1502A (Tweener PRT readout) and 1504 (Tweener thermistor readout) are compact, single-channel thermometer readouts for laboratory and field reference use. Each unit converts measured resistance to temperature using built-in ITS-90/IPTS-68/Steinhart‑Hart algorithms and can be programmed with probe constants for maximum linearity.


1502A — PRT/RTD readout

• Supports 100 Ω, 25 Ω and 10 Ω RTD/PRT/SPRT probes (nominal RTPW 10–100 Ω).
• Resistance range 0 Ω–400 Ω (auto-ranging); resistance resolution to 0.0001 Ω.
• Temperature range −200 °C to 962 °C; accuracy examples: ±0.004 °C at −100 °C, ±0.006 °C at 0 °C.
• Front-panel digital calibration; small footprint for bench or portable use.

1504 — Thermistor readout

• Designed for thermistors with Steinhart‑Hart and Callendar‑Van Dusen characterizations.
• Resistance range up to 1 MΩ (auto-ranging); resolution and accuracy optimized for limited temperature spans.
• Typical accuracy ±0.002 °C at 0–25 °C (depends on sensor and characterization).
• Resolution to 0.0001 °C; low excitation currents for thermistor measurement.

Advanced features & software

• Programmable probe constants (R0, alpha, coefficients) for improved linearity.
• Display in °C, °F, K or resistance in ohms; exponential digital filter (0–60 s).
• Data acquisition via LogWare 9934; integration with MET/TEMP II for automated calibrations.
• RS-232 standard, IEEE‑488 (GPIB) optional; front-panel calibration—no need to open unit.

Specifications (summary)

• Temperature range: 1502A −200 °C to 962 °C; 1504 per thermistor range (example 0–100 °C).
• Resistance range: 1502A 0–400 Ω; 1504 0–1 MΩ (auto-ranging).
• Temperature resolution: 1502A 0.001 °C; 1504 0.0001 °C.
• Measurement period: 1 s (up to 2 readings/s).
• Display: 8-digit, 7-seg yellow-green LED, 0.5 in characters.
• Power: 115/230 VAC selectable; optional battery pack available.
• Dimensions: 61 x 143 x 181 mm; Weight: ~1.0 kg.
• Calibration: ISO 17025-accredited calibration available.

Typical applications

• Laboratory and on-site reference temperature measurements.
• Calibration laboratories using PRT/RTD or thermistor references.
• System checks where high resolution and traceable calibration are required.