Labconco PURICARE Procedure Station Models 31260 User Manual
Page 71
Product Service 1-800-522-7658
71
Logic+ Filter Life Gauge Operation and
Resetting for Local Conditions
The filter life gauge calculates the remaining filter life by measuring and comparing the current
motor speed to the initial speed noted at the factory during assembly, and the calculated
maximum motor speed, using the formula:
100-(100x (current speed-original speed) ) = % filter life left
max. speed-original speed
So
anything
that changes the motor’s current speed, like:
Blocking the grille.
Raising the air temperature.
Lowering the barometric pressure.
will increase the motor’s speed, causing the Filter Life Gauge to decrease. Electronic dampening
of the gauge will limit the change in readings to approximately 1%/minute.
Logic+ Biosafety Cabinets being installed at altitudes or operating at temperatures significantly
different from those at the time of manufacture (900 +/- 500 ft above sea level, 75
o
+/- 5
o
F)
must
have their filter life gauge recalibrated for local conditions. Failure to do so will result in the
users noticing a steady drop in Percent (%) Filter Life remaining as the unit operates. Below are
the instructions on how to correct the Filter Life Gauge for local conditions.
1.
Ensure to correct all measurement equipment for local conditions (temperature, absolute
pressure). Anemometers may not have this ability and might have to be done manually;
whereas, a ShortRidge
TM
instrument has a setting to correct for local conditions.
2.
As the elevation or the ambient temperature rises, the motor power factor will have to be
reduced to compensate. For an initial certification, the motor speed should be reduced
until it equals the Logic+’s “Initial Motor Speed” as reported on the unit’s test sheet, plus
approximately 10-15 RPM per each additional 1000 feet of elevation.
3.
The Logic+ MUST be recertified using instruments corrected for local conditions.
4.
When the unit is recertified, and operating properly, the certifier MUST RESET THE
FILTER LIFE GAUGE, INDICATING A NEW FILTER HAS BEEN INSTALLED.
5.
Only by performing Step #4 AFTER THE UNIT IS READJUSTED AND RECERTIFIED FOR
ITS LOCAL CONDITION, will the filter life gauge register 100% (+/- 2%) during
operation. As the Filters then load, the filter life gauge will then begin to drop as
appropriate.
6.
If you do not wish to reset the filter gauge, select the option “Filter not changed”, and
press “Mute/OK”.
7.
Either selection will finish the calibration mode, or lead to calibration of inflow and
downflow velocities.