Wahl Heat Spy DHS520, Руководство пользователя

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Wahl DHS520
6.0 OPTICS
User Manual
The Wahl DHS520/520B has a precision reflex optical system, which provides
user-focusable ‘through the lens’ sighting and gives precise definition of the
target spot. The specified focal range is 1m/39.4in to infinity.
6.1 Target Size Calculation
The precision reflex optical system gives a narrow field of view (180:1 to 98%
energy).
As the instrument is focusable, you can calculate an approximate target size
from the information given in Fig. 15.
target distance (D) from optical datum
field of view
optical
datum
target size (T)
Not to scale
target diameter (T) (mm) = target distance (D) from optical datum (mm) - 100
field of view (180)
or
target diameter (T) (in) = target distance (D) from optical datum (in) - 4
field of view (180)
315015
Fig. 15 Wahl DHS520/520B thermometer target size calculation