The Wahl DHS520 is a general purpose, high precision, portable infrared thermometer, designed for accurate temperature measurement in the range of 1022° to 5432°F (550° to 3000°C). The bright, back-lit external display panel indicates status and configuration of thermometer, together with four simultaneous modes: continuous, average, maximum and minimum.
Accurate sighting is ensured by the clear, wide angle (9°) field of view and small, clearly defined (1/3°) measurement area. Focusing is variable from 1m to infinity, with close focus options available using auxiliary lenses. Reflex optical system gives precise definition of target spot and simultaneous backlit display of user selected values in the viewfinder.
Emissivity compensation is provided via the icon-based menu system. The operating waveband has been carefully chosen to minimize errors due to uncertainty in emissivity and the effects of atmospheric vapor components.
| Distance: ft (m) | Target Size: in (mm) |
| 328 (100) | 22.6 (576) |
| 164 (50) | 11.2 (287) |
| 65.6 (20) | 4.48 (114) |
| 32.8 (10) | 2.24 (57) |
| 22.9 (7) | 1.53 (39) |
| 16.4 (5) | 1.10 (28) |
| 6.5 (2) | 0.43 (11) |
| 3.2 (1) | 0.18 (4.8) |
Target size can be reduced to a minimum of 0.4mm/0.016in with optional close-up lenses.