Fluke Reference Thermometer

1523 and 1524 Reference Thermometer

Fluke Calibration's 1523/24 Reference Thermometers measure, graph, and record PRTs, thermocouples, and thermistors; the handheld tool delivers exceptional accuracy and wide measurement range in a versatile instrument you can take anywhere. The 1523/24 lets you handle field applications, laboratory measurements, and data logging with ease. And with dual channel measurement capabilities of the model 1524, you can do twice the work in half the time.

Fluke 1523/24 Reference Thermometers are designed for accuracy, precision, and compliance with the latest safety standards. The 1523/24 uses current reversal, a technique used in high-end instruments that eliminates thermal EMFs (electromagnetic forces) for precision temperature measurements. Specifications are guaranteed from –10 °C to 60 °C ambient. Special precision resistors and a highly stable reference voltage source keep accuracy virtually insensitive to environmental temperature. Like all Fluke handheld tools, 1523/24 Reference Thermometers come with a two-year warranty and free lifetime technical support.

Three sensor types

• PRTs: –200 °C to 1000 °C

• Thermocouples –200 °C to 2315 °C

• Precision thermistors: –50 °C to 150 °C


• PRTs: up to ± 0.011 °C

• Thermocouples : ± 0.24 °C for J,K,L,M

• Precision thermistors: ± 0.002 °C

Fast mode

• PRTs: 0.45 seconds per sample

• Thermocouples: 0.3 seconds per sample

• Thermistors: 0.3 seconds per sample

Two models

• 1523: Single channel standard model;

memory for 25 readings and statistics

• 1524: Two channels; memory for

logging 15,000 measurements; realtime

clock for time and date stamps

Graphical display

• 128x64 backlit LCD graphic display

• Plot and scale trends in real time

• Simultaneous dual channel readings

Suitable for various types of probe

Single or two channel models

Handheld tool you can take anywhere

Highly accurate & wide measurement range

Key information



Input Channels




25 readings with statistics

25 readings with statistics
15,000 time and date

Sample interval

1 second

1 second (simultaneous

Typical sample
interval (fast mode)*

0.3 seconds

0.3 seconds

Sensor Types

Sensor types PRTs, RTDs, Thermistors, and Thermocouples

Thermocouple types 


Operating temperature 

–10 °C to 60 °C (Best accuracy 13 °C to 33 °C)

Power requirements

3 AA alkaline batteries


EN 61010-1:2001, CAN/CSA C22.2

No. 61010.1-04

Size (HxWxL)

96 mm x 200 mm x 47 mm
(3.75 in x 7.9 in x 1.86 in)


0.65 kg (1.4 lb)

Fluke probe selection

Choosing the right probe

It is important to select a reference probe that covers the full temperature range of the sensor application. We have a number of fluke probes available all offering different benefits for the requirements of the user. There are 5 key probe types that are compatible with the Fluke reference thermometer, those being: Standard reference PRT, Precision industrial PRT, Secondary standard PRT, Full immersion PRT and Thermistor secondary probe. We have a table below that highlights the key data such as probe range and accuracy. The table should help in deciding the correct probe for your application, however, if you need some additional assistance then get in touch and one of our technical sales team will be happy to help select the correct probe for your requirements. 

Key information


Probe Range

Junction Range


Basic Accuracy


Secondary Reference PRT


–200°C to 200°C 

–50°C to 200°C 

152 mm x 4.76 mm

± 0.013°C at 0.010°C

100 mm


 –200°C to 420°C

–50°C to 200°C 

229 mm x 4.76 mm

± 0.013°C at 0.010°C

100 mm


–200°C to 420°C 

–50°C to 200°C 

305 mm x 6.35 mm

± 0.013°C at 0.010°C

127 mm

Precision Industrial PRT


 –200°C to 300°C

 0°C to 150°C

152 mm x 4.7 mm

± 0.05°C at 0°C

100 mm


–200°C to 300°C 

0°C to 150°C 

229 mm x 4.7 mm

± 0.05°C at 0°C

100 mm


–200°C to 420°C

 0°C to 150°C 

305 mm x 6.35 mm

± 0.05°C at 0°C

127 mm

Secondary Standard PRT


–200°C to 661°C

0°C to 80°C 

305 or 381 mm x
6.35 mm

± 0.006 °C at 0 °C

 127 mm

Full Immersion PRT


 –200°C to 160°C

 –200°C to 160°C

50 mm x 3.1 mm

± 0.05 °C

76 mm

Thermistor Secondary Probe


0 °C to 100 °C 

0 °C to 100 °C

152 or 229 mm x
3.2 mm

± 0.01 °C

76 mm