32
Subsequently pressing
set
will scroll through the available memory sizes
from 1K to 30K in 1K increments and thereafter in 20K increments.
Holding down
set
will allow you to scroll through the memory sizes faster.
4.10.4 Sensor power on facility
S T A T s e n s o r o n
1 0 s e c o n d s
Some voltage/current channels have additional connections to allow
sensors to be supplied with power from logger. All models allow this
power to be set at either 9V DC or 5V DC. This setting can be changed
only by dismantling the logger and moving the jumpers for each output as
required. See section 12.10 for more information on moving the jumpers.
The 9V setting is only approximate. The voltage is that of the internal
batteries or the 12V external power supply, if present. The 5V DC is
accurate to ±0.1%. Some sensors need to be switched on prior to
measurement for a minimum length of time to allow the output to stabilise.
This facility allows you to switch the sensor on between 1 second and 60
seconds (in 1 second increments) prior to measurement; all sensor power
outputs will turn on together. The maximum total current available is 50
mA. If you have more than 1 sensor connected which needs this facility
then you must choose the longest sensor switch on time required. The
sensor switch on time may be changed by pressing and holding set;
subsequent presses will allow you to scroll through the values. Holding
down set will allow you to scroll through the values faster. A value of 0
seconds switches the sensor power on 10 milliseconds before the first
channel is read.
Please note that in logging modes which combine event with interval or
average logging, the
‘sensor on’ time is measured with respect to the fixed
interval or sample time respectively. Therefore, no particular
‘sensor on’
time can be guaranteed for the event recordings. However, in
‘event only’
logging, any non-zero
‘sensor-on’ time setting causes the sensor power
output to be on continuously.
N.B. The
‘sensor on’ time should be set to zero when not required as
otherwise battery life will be wasted.
