Industrial Fiber Optics IF-FOM, Руководство оператора

Страница: 9 / 26

– 3 –
LED Activation
The “LED ACTIVATION” push-button is a momentary switch which turns on the built-
in LED source for approximately 10 minutes, after which the LED turns off to conserve
battery life.
Wavelength
The “WAVELENGTH” slide switch adjusts the sensitivity of the radiometer at two factory
calibrated wavelengths, 650 nm (visible red) and 850 nm (near-infrared).
Zero
The “ZERO” hole provides screwdriver access for an adjustment that sets the LCD display
indication to zero when there is no incoming light on the radiometer detector.
Display
The indicator for the digital radiometer is a Liquid Crystal Display (LCD) with 3-1/2
digit resolution. The maximum valid numerical reading is 1999 and the minimum is 0.
When the display has a non-zero or negative reading with no light on the radiometer, the
“Zeroing” procedure in the section titled SERVICE AND MAINTENANCE should
be performed.
Receptacles
Detector
The receptacle labeled “DETECTOR” contains the optical sensor for the radiometer
to measure power from fi ber optic cables. Optical power absorbed by the detector is
converted to an electrical signal which is amplifi ed and shown on the LCD display. The
detector is a silicon photodiode approximately 6.6 mm2 (0.01 inches2) which has a peak
response at 850 nm. The receptacle is a female “ST
®
” bayonet style fi ber optic connector,
which accepts the popular ST
®
male plug used with plastic jacketed fi ber optic cables.
Un-connectorized cables may also be inserted into this receptacle for measurements. The
plastic cap over the ST
®
receptacle protects the internal detector from damage and dust.
The cap must be removed prior to measurement and should be replaced when the test set
is not in use.