The Hagner Digital Lux/Footcandle
Photometer TP200
The Hagner Digital Photometer, model TP200, is a small, handy and extremely easy-to-use
instrument for accurate measurement of illuminance. It has two ranges for measurement of
both metric, lux (Ix) and imperial, footcandle (fc) units. The scales are chosen by setting the
switch above the digital display. The sensitivity ranges are 0.1-200,000 Ix and 0.01-20,000
fc. With both automatic zeroing and on/off switch, the only controls needed are a fourposition
range selection switch and a hold button for retaining the display value.
Operation
To open the lid, press the forward part lightly downward with your thumb and at the same
time pull the latch upwards with the first two fingers of the same hand. The photometer
comes on when the cover is opened and turns off when it is closed. Move the range switch
to the range which will give the greatest accuracy and read the display.
The hold function keeps the reading on the display until the hold button is released. Full
instructions can be found on the inside of the cover.
Maintenance
The power source is a standard 9 volt battery. To avoid battery leakage only alkaline
batteries should be used. When LOBAT appears on the display, it is time to replace the
battery. The photometer can however be used for approximately 20 hours longer before
replacement is necessary.
Change the battery by removing the screw at the front edge of the cover plate, which
permits the plate to be lifted up and removed. When replacing it, the lower edge of the
plate must fit under the two bosses at the lower edge of the case before it can be closed
again.
The white plastic disc over the detector may be cleaned when necessary with a lightly
damped cloth.
Calibration
The luxmeter is carefully calibrated when delivered. As the light sensitive silicon diode is
extremely stable over long periods of time recalibration every two-three years should,
under normal use of the instrument, be sufficient. If however there is any reason to believe
that the instrument is out of calibration, it can be returned to your stockist or the
manufacturer for earlier control checks.