ThermoFisher Scientific Wellwash 4, Service Manual

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Chapter 4: Functional Description
Thermo Scientific Wellwash
®
4 Mk 2 User Manual Rev.2.3, Cat. no. 1507340 11
4 Functional Description
The Wellwash 4 Mk 2 is designed to wash wells in an 8 x 12 microplate. It
comprises a pump unit and a washer unit (Fig. 4.1), which are connected by
power, air and liquid lines.
The pump unit consists of a double-headed vacuum pump with high-density
polythene reagent and waste bottles and a liquid trap. The main power ON/OFF
switch is at the rear of the pump unit. The frequency selector switch is located
on the bottom side of the pump model Cat. no. 5190771 near the transport
locking screws.
The keypad is located on the left-hand side of the washer unit and the
microprocessor and associated control electronics are housed under the
keypad. The wash head is located above the plate carrier slideway, which can
be either 8- or 12-way. The plate carrier moves the microplate accurately
beneath the wash head and incorporates a priming reservoir at its leading edge.
The plate carrier is indexed forward by means of a magnetic coupling to the
drive system housed inside the washer.
1. Pump unit 8. Wash arm assembly
2. Washer unit 9. Wash head and wash head holders
3. Waste bottle 10. Priming reservoir
4. Wash bottle 11. Keypad
5. Bottle caps 12. Plate carrier
6. Liquid level sensor 13. Program card
7. Liquid trap bottle 14. Pinch valve
Fig. 4.1 Wellwash 4 Mk 2 microplate washer
The pump creates pressure to the wash bottle (Fig. 4.1, item 4) allowing the
wash liquid to be dispensed through the pinch valve (Fig. 4.1, item 14) into the
microplate wells and a vacuum to the waste bottle (Fig. 4.1, item 3) to aspirate
the used wash liquid into the waste bottle.
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