Parker SciLog LabTec Installation, Operating, & Maintenance Instructions page 47

3.3 Volume Dispense Mode: Calibration
The LabTec™ has two volumetric calibration features, built in Factory Calibrations as well as
a Re-Cal feature.
The LabTec™ utilizes a number of factory calibrations. The LabTec™ accesses built in calibration
curves based upon the motor rpm setting in SETUP: Pump: Motor RPM, the head setting in SETUP:
Pump: Pump Head and the Tubing setting. When using a peristaltic head, select the correct tubing
and you're ready to optimize and finally perform a RE-CAL (see below).
Calibrations for RH series heads are based on a vernier setting of 200, and those for the Magnetic
gear heads are specific to that head. Again, a simple optimization and RE-CAL, and you're done. If you
have not requested Parker to pre-configure and optimize the dispensing aliquots for you, or are
editing a new one, you need to confirm the aforementioned settings.
Optimization involves choosing and fine-tuning the Pump Speed and Slow Factor settings to obtain
fast, precise aliquots without overshooting. Small aliquots require slower pump speeds than large
ones, and a similar relationship with aliquot size, pump speed and Slow Factor exists. Faster pump
speeds will require larger Slow Factors. Please refer to Part C of this manual for example dispensing
parameters that will provide a good starting point.
The Re-Cal feature allows you to quickly update the Factory Calibration. For peristaltic pumps in par-
ticular, slow pump tube wear will change the pump output over time. The Re-Cal function will com-
pensate for this change in pump output by
adjusting the stored calibration curve.
For re-calibration purposes, you should dispense at least three (3) aliquots (distilled water) of your
selected volume; e.g. 150.00 mL. Record the weight of each aliquot, and then determine the average
(AV) aliquot weight. Use an electronic top-loading scale to weigh each aliquot.
For example, assume that you obtained the following values:
In this example, you would adjust (assume 1.00 mL = 1.00 grams) the AV parameter to 152.13; the
LabTec™ will automatically correct the factory calibration curve.
The Re-Cal feature is accessible through the Re-Cal key on the LabTec™ front panel. As shown on the
opposite page, the Re-Cal feature is active when the following is displayed.
Press the Re-Cal key on the front panel, and the following display appears:
Only the AV parameter (AV= Average Value) can be changed in this display, use the "Incr." and "Decr."
keys to adjust the AV parameter to match the amount collected. You may want to repeat the Re-Cal in
order to check the improved dispensing accuracy.
Trial 1 152.50 g
Trial 2 151.80 g
Trial 3 152.10 g
AV = Average Value: 152.13 g
DISPENSING
Completed
DV = 150.00
Incr. Decr.
AV = 150.00
Select
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