An Australian University Research Laboratory was wishing to manufacture an automated system to allow preparation of medical samples using the method of Solid Phase Extraction.
To measure this, a linear sampling device which can hold up 10 solid-phase extraction cartridges was built. A computer was used to specify which cartridge to use and the plate moved into the correct position (stepper motors are used for all movements). To connect a cartridge, one connector moves downwards from the top, then the other one comes in from the bottom.
The load cells were to be installed to determine the point when the connections are made. A voltage signal was sent when the calibrated voltage was reached and the motor shut off. Once the cartridge was connected, our customer could start the solid-phase extraction procedure by pumping liquid from top to bottom through the cartridge.
Metromatics were able to offer a Futek Load Cell which interfaced with an Acromag Strain Gauge amplifier with a programmable limit switch to shut off the motor once the calibrated voltage was reached.