
BF5 User Manual v 2.3
Technical reference
35
Routine Maintenance
Batteries
The BF5 is provided with internal batteries, but can also be powered from
an external data logger via the round 5-pin connector. It can also take
power from the heater power supply and from the RS232 serial cable.
It will draw power from whatever source has the highest voltage.
Using the internal batteries will prevent any current drain from an external
logger, and remove any signal errors due to power supply currents in the
cable.
The Total & Diffuse radiation and Sunshine Status become active at the 8
pin analogue connector within 100ms of power (>4V) being applied to the
DL-Power warm-up pin. The BF5 will automatically sleep when external
power is removed.
The BF5 internal batteries should usually last for about 12 months,
depending on logging frequency.
Do not leave the BF5 with exhausted batteries in it; they may leak.
Desiccant
The dryness of the desiccant pack is indicated by a coloured panel under
the dome. Blue indicates dry, pink indicates that renewal is needed.
To regenerate the desiccant.
The desiccant pack can be regenerated by heating. Remove the pack
from the BF5 and heat in an oven for a few hours at about 90ºC. Allow it
to cool down away from moisture before reinstalling it.
Maintaining the dome
Air pollution and residues in rain and snow can make the dome quite dirty.
A clean dome is essential to maintain the accuracy of the BF5.
The dome is acrylic and damaged by many solvents. Clean it when
necessary with a damp cloth, moistened with mild detergent.
If the dome cannot be cleaned satisfactorily, please contact Delta-T about
a replacement dome option or factory service.
Recalibration of BF5
We recommend that BF5s are returned every 2 years to Delta-T for
recalibration. A calibration certificate similar to the one below will be
provided.