The Hagner Digital Luxmeter EC1
The Hagner Digital Luxmeter, model EC1, is a small, handy and extremely easy-to-use instrument for accurate measurement of illuminance over a range of 0.1-200,000 lux. With both automatic zeroing and on/off switch, the only controls needed are a four-position range selection switch and a hold button for retaining the display value.
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 luxmeter 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.
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. However the luxmeter can be used for approximately 20 hours longer before replacing 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 light damp cloth.
The luxmeter is carefully calibrated when delivered. As the light sensitive silicon diodes are 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 belive that the instrument is out of calibration, it can be returned to your stockist or the manufacturer for earlier control checks.