Labconco PURICARE Procedure Station Models 34812xx - Manual (Page 15)

Page 15 of 197
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:
9 Blocking the grille.
9 Raising the air temperature.
9 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.