The Fluke Calibration 1524 Reference Thermometer is a handheld two-channel readout that measures, graphs, and records temperature from three different sensor families — PRTs, thermocouples, and precision thermistors — through a single tool. It is the two-channel member of the 1523/1524 family, sharing every measurement feature of the single-channel 1523 while adding a second input channel, memory for 15,000 time and date stamped measurements, and a real-time clock for date-stamped logging.

The datasheet identifies calibration, loop checking, conformance testing, troubleshooting, maintenance, repair, and logging and validation as the applications this instrument is built for. Specific use locations called out include baths, dry-block calibrators, thermowells, clean rooms, engines, heat exchangers, furnaces, and freezers. The two-channel architecture is positioned for differential measurement work — testing internal and external combustion engines, turbines, steam systems, cooling towers, heat exchangers, and refrigeration systems where inlet-to-outlet temperature differences need to be measured, calculated, and recorded simultaneously.

ValueTronics is an authorized distributor for Fluke Calibration products and stocks the 1523 and 1524 Reference Thermometers in our 20,000 sq ft secure warehouse at 1675 Cambridge Drive, Elgin, Illinois. Every unit is inventoried, inspected, and shipped directly from our facility — not drop-shipped from a third-party warehouse — so the instrument that ships is the instrument our team has hands on. Operating from a single owned facility since 1992, we keep both new authorized stock and verified pre-owned reference thermometers available, with our test and calibration team able to confirm condition and configuration before any unit leaves the building.

Brand Heritage

Fluke Calibration is the precision calibration instruments division of Fluke Corporation. The 1523 and 1524 readouts trace directly to the Hart Scientific product line; Hart Scientific was acquired by Fluke and the precision temperature calibration product family — including reference thermometer readouts, dry-block calibrators, and temperature baths — was consolidated under the Fluke Calibration brand. Hart Scientific instruments and the Fluke Calibration successors share the same engineering pedigree, calibration laboratory infrastructure, and the NVLAP-accredited temperature calibration capability (NVLAP Lab Code 200348-0) referenced in the datasheet.

Compare Other Models in This Series

The Fluke Calibration 1523/1524 Reference Thermometer family is a two-model handheld lineup sharing one measurement engine. Both readouts measure PRTs, thermocouples, and precision thermistors with the same accuracy specifications, the same INFO-CON probe interface, the same 128x64 backlit graphical display, and the same 12 thermocouple types. The structural difference is channel count and data logging capacity: the 1523 is a single-channel readout with memory for 25 readings plus statistics; the 1524 adds a second input channel, a real-time clock, and memory for 15,000 time and date stamped measurements.

Choosing between the two is an application question, not a precision question. Both instruments deliver the same per-measurement accuracy. The decision is whether the work requires simultaneous two-channel measurement (differential temperature, inlet-to-outlet comparisons, two devices under test in parallel) and whether data logging beyond the 25-reading manual save buffer is needed.

Each new 1523 and 1524 below is its own dedicated product page with condition-matched pricing, full configuration details, and current availability from our Elgin facility.

The 1524 is the right choice when the measurement scenario involves two sensors at the same time — engine inlet and outlet temperatures, two-zone process monitoring, simultaneous calibration of paired workload, or any scenario where channel-to-channel temperature difference is the result of interest. The 1524 calculates and displays the difference between channels directly. Memory for 15,000 time and date stamped measurements supports independent logging without a connected PC, which the datasheet specifically positions for space-constrained installations and field validation work.

The 1523 stores 25 readings with statistics — adequate for documentation of discrete check measurements but not for continuous time-stamped logging. The 1524 stores 15,000 time and date stamped measurements with a real-time clock, supports user-selectable sample rates from seven per second down to once per hour, and accepts probes on both Channel 1 and Channel 2 (Channel 1 accepts PRT, thermocouple, or thermistor; Channel 2 accepts PRT or thermistor per the rear-panel detail).

Both readouts share identical PRT, thermocouple, and thermistor accuracies; the same –10 °C to 60 °C ambient operating range with best accuracy from 13 °C to 33 °C; the same RS-232 serial interface; and the same 3-AA-battery power architecture with 20+ hours of runtime or continuous operation from the included AC adapter. See the comparison table below for the channel-count and logging-capacity differences side by side.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Accessories Supplied

• 1524 Reference Thermometer Readout
• 5627A PRT
• Universal TC INFO-CON Connector
• TPAK Meter Hanging Kit
• Case
• 3 AA batteries
• AC adapter with power cord
• RS-232 cable
• Users guide
• Documentation CD
• Report of calibration and calibration label
• Clamp-on ferrite(s)

Product Core & Specifications

Equivalent Temperature Accuracies with Selected Probes (± °C)

Includes readout accuracy, probe calibration, and probe drift.

Thermocouple Temperature Accuracies

Resolution (B, C, E, J, K, L, M, N, R, S, T, U): 0.10 °C. Accuracies are based on internal reference junction compensation. Refer to technical manual for equivalent accuracies with an external reference junction.

Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.