NOTE:
If the built-in temperature device is not a thermistor, measure only the resistance of the
device in ohms. If it is a thermistor that follows the Steinhart-Hart conversion formula, you
have the option to convert the thermistor resistance output into degrees Celsius. Refer to the
sensor manual to know which kind of temperature device you have.
7.3 Providing temporary power to the
CRVW3
To provide temporary power to the CRVW3 while in the lab, it is recommended that you use a 16
to 28 VDC power supply. Connect the power wires to the Charge terminals.
Figure
7-3.
Power
source
connection
If
your
CRVW3
uses
the
–ALK
option,
you
can
disconnect
that
power
source
to
preserve
battery
life
while
power
is
applied
to
the
charge
terminals.
When
using
the
–RC
option,
you
can
leave
the
rechargeable
battery
connected,
and
the
charge
circuit
will
charge
the
battery
while
the
device
is
powered.
You
can
also
power
the
device
through
the
terminals
when
no
battery
is
present.
The
USB
connection
supplies
5 VDC
power
as
well
as
a
direct
communications
link,
which
is
adequate
for
setup.
12 VDC
power
will
be
needed
for
field
deployment
and
radio
communications.
Measurements
made
while
powered
only
with
USB
will
result
in
NAN
(not
a
number)
for
measurement
output.
See
for
LED
behavio
u
r.
CRVW3 3-Channel Vibrating-Wire Data Logger
19