ST680 Series
High Performance Handheld Infrared Thermometer


  • High-performance, temperature gun-style infrared thermometer
  • Temperature range: -50°C to 1000°C
  • Laser sighting with on/off switch
  • Adjustable emissivity 0.1 to 1.0, ideal for surface temperature measurement of many materials including food
  • Precision 50:1 germanium optics
  • Audible alarms
  • 10 point memory
  • Tripod mount


  • All the features of the ST688, plus:
  • USB data output for temperature display and logging
  • USB cable and software supplied
  • Type K thermocouple input
ST688 ST689
Emissivity Setting Adjustable 0.1 to 1.0 Adjustable 0.1 to 1.0
Type K Thermocouple Input NO YES
USB Data Output, Cable and Software Supplied NO YES
Audible Alarm YES YES
°C/°F Switchable YES YES
Display Backlight YES YES
Laser Sight, Switchable YES YES
Max, Min, Avg, ΔT YES YES
Tripod Mount YES YES
Hard Carrying Case Included YES YES

General Specifications

Field of View
Temperature Range
-50°C to 1000°C (-58°F to 1832°F)
±3°C (±5°F) from -50°C to -20°C (-25°F to -4°F)
±2°C (±3°F) from -20°C to 100°C (-4°F to 212°F)
±2% above 100°C (212°F)
Spectral Range
8 to 14 μm
±1°C (±2°F)
0.1°C (0.1°F)
Response Time
500 ms
Operating Temperature
0°C to 50°C (32°F to 122°F), 10% to 90% RH
Power Off
Automatic after approximately 6 seconds
4-digit LCD with backlighting
Battery Type
9 V, PP3 (not supplied)
200 x 127 x 47 mm
330 g
Model Description Price
ST688 High-performance handheld infrared thermometer with hard carry case Contact Calex
ST689 High-performance handheld infrared thermometer with USB interface, USB cable and software, Type K thermocouple input, and hard carry case Contact Calex