Honeywell Hand Pump

This is a piston-type hand pump that draws a fixed volume of gas which is selectable at either 50ml or 100ml by rotating the handle. There is a tight vacuum seal which has been formed by a greased plunger gasket. A range of tube diameters for different types of tubes are accomodated by a tapered rubber inlet. Dust and glass pieces are prevented from entering the shaft by the inlet filter. When the gas sampling is complete an end-of-flow indicator in the handle turns. A pump stroke counter is rotated in order to keep track of the number of strokes completed.