7
5.3
Dispensing By Weight: Parameter Guide,
Magnetic Gear Pump:
The following information should be used as a general guide in selecting optimal dispensing
parameters. This data was collected with a 3400 RPM LabTec™ Dispenser mounted with a
201 Micropump Head. A check valve (P/N: 400-530) was used as a dispensing spout.
The “Slow Factor” is implemented at the end of each dispensing cycle to allow the electronic scale to
stabilize. Thus a Slow Factor of 25 mL indicates that the last 25 gr will be dispensed at reduced pump
speed.
The end of the dispensing cycle will be indicated by a “beep” followed by the display “Dispensing
Completed”. The “Sniffl ” function is turned off i.e. Sniffle = 0.0.
Edit 1: Dispensed Weight 2000 to 500 gr: Disp. Weight = 2000 gr, Sniffle = 0.0, Slow Factor = 25 gr,
Pump Rate = 100%, Time Delay = 0.1 sec, Count = 5.
Edit 2: Dispensed Weight 500 to 100 gr: Disp. Weight = 500 gr, Sniffle = 0.0, Slow Factor = 25 gr, Pump
Rate = 70%, Time delay = 0.1 sec, Count = 5
Weight
Ave. Dispensed Dispensing Time
Set
Weight
RSD (%)
per Aliquot
EXEC 1: Pump Rate = 100%, Slow Factor = 80 gr
2000.00 gr 2000.7 gr 0.02% 42 sec
1500.00 gr 1501.2 gr 0.02% 34 sec
1000.00 gr 1001.2 gr 0.04% 24 sec
500.00 gr 501.2 gr 0.04% 16 sec
EXEC 2: Pump Rate = 80%, Slow Factor = 50 gr
500.00 gr 500.5 gr 0.08% 19 sec
400.00 gr 400.9 gr 0.05% 17 sec
300.00 gr 300.6 gr 0.05% 13 sec
200.00 gr 200.5 gr 0.11% 11 sec
100.00 gr 100.6 gr 0.25% 9 sec
Note: The LabTec™ will stop pumping just prior to reaching the target weight; once the scale has
stabilized, the LabTec™ will complete the dispensing cycle.
Note: Increase the Slow Factor 35gr or 45gr if the pump does not stop prior to completion of the
dispensing cycle. If the pump does not stop, it is an indication that the pump has either overshot
the target weight or that the dispensed weight is within specified margin of error.
Edit Parameters: All dispensing was done with a 201 Micropump Head.
Note: Distilled water was used as a diluent; five (5) separate measurements were made for each
of the sample weights. Each aliquot was weighed on a PG 5002-S Mettler scale, readability
0.01 gr. The average Delivered Diluent Weight and the Relative Standard Deviation (RSD) are
summarized above.
To Next Page
Loading...
