Delta OHM HD 9221 Manual De Instrucciones página 30

ENGLISH
Solar constant
The mean IRRADIANCE of the sun, before the modifications due to the
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earth's atmosphere at a mean distance of 1.5 x 10 metres from the earth,
2
is estimated to be 1353 W/m .
Illuminance constant
The currently accepted value of solar ILLUMINANCE, with normal surface
incidence in a free space at a mean distance of the earth from the sun, is
127.5 klux.
LOW BATTERY WARNING AND BATTERY REPLACEMENT
H
If the battery voltage falls below a certain level, the symbol appears on
the display. From that moment there remains about 1 hour autonomous
operation. The battery should be replaced as soon as possible, otherwise,
if the voltage falls even further, the data shown are no longer correct; the
battery symbol disappears. The battery used is an ordinary 9V zinc-carbon
battery, IEC 6LF22.
To change the battery, unscrew the cross-headed screw on the door of the
battery compartment,
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