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381a Non-Contact/Contact IR Thermometer

The 381a is a non-contact and contact temperature tester with laser sighting to confirm your target. It uses K-type thermocouples with sub-mini connector for contact measurements.

  • Contact and non-contact thermometer
  • Maintain reading on display
  • Laser sighting
  • Backlit display
  • 9:1 distance to spot ratio
  • 0.1 degree resolution
  • 095 emissivity
  • 3 Year Limited Warranty

£65.00 RRP exc. VAT

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Frequently Asked Questions

  1. What does “distance to spot ratio” mean?
    The laser spot needs to be showing inside the target area. An 8:1 “distance to spot ratio” means you are measuring a 1” diameter area at a distance of 8”.
  2. How far can I measure?
    Distance is unlimited. The size of the target area sets the limit on distance for accurate measurements. Example: If the area you wish to measure is 1 foot in diameter, then you will need to be within 8 feet to record an accurate temperature.
  3. What is the smallest target I can read?
    Approximately one-half inch in diameter.
  4. What is emmisivity?
    This is a ratio of an object’s infrared emission compared to a theoretical black body considered 1. Emissivity is always less than 1. Adjustable emissivity allows your non-contact thermometer to be adjusted to the surface you are checking to make readings more accurate.


 Model 381a Specifications
 Temperature Range  Non-contact: -4° to 572°F (-20° to 300°C)
 Contact:* -148° to 2192°F (-100° to 1200°C)
 IR Accuracy @ 23°C and 0.95 emissivity  ± 5°F (3°C) below 32°F (0°C)
 32°F to 572°F (0°C to 300°C) ± 2% of rdg
 or ± 3.5°F (2°C) whichever is greater
 Contact Accuracy  +(0.5% of reading + 3.5°F (2°C)
 Distance to Spot Ratio  9:1
 Response Time  500mS
 Spectral Response  7 to 14um
 Emissivity  0.95 Fixed
 Laser Sighting  Output <1mW, Wavelength 645-660nm, Class II Laser
 °F or °C  Selectable (slide switch in handle)
 Contact or Non-contact  Selectable (slide switch in handle)
 Display Hold  Yes
 Operating Temperature  32°F to 120°F (0°C to 50°C)
 Battery Type  9V

* Depends upon temperature probe range

381a Applications

  • Ideal for under-floor heating
  • Check for cold spots on radiators
  • Read temperatures in Hard to Reach Areas

Distance to Spot Ratios (D:S) for TPI IR (Non-contact) Thermometers:

Models 375 / 376 / 377 (11.5:1):








Models 380 / 381 / 383 / 384 (9:1):


TPI 381 Demonstration Video

Product Documentationpdf-icon1

Click below to view or download product documentation PDFs:

381a Manual

381a Data Sheet

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