
BF5 User Manual v 2.3
Use with a data logger
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The Total and Diffuse outputs are protected from electrostatic discharge
(ESD) by the transient voltage suppressors TZ4-6, and from low voltage
misconnection by the zener clamps D7 & D8, and resettable fuses F3 &
F4 (the fuses reset when the fault is removed). The Sun output has similar
protection against ESD and overcurrent.
The heater circuit is protected against reverse connection and
overcurrent. Htr- is connected to the main sensor ground by an inductor,
to protect it from any noise in the heater circuit.
The serial port lines have basic ESD protection.
Suggested power supply connections
For use with a data logger, the DL-Power line has to be at 5V or more to
enable the analogue outputs. The power required can be taken either from
the DL-Power line, or the heater supply. For most logging situations, one
of the following two connections is recommended.
1 No heater, BF5 powered by logger warmup
This connection would be appropriate for an isolated, battery powered
logger such as the Delta-T
GP1
. The BF5 heater is left disconnected.
The logger must power up the BF5 at least 100ms before the reading
is taken.