Flow measurement device
First Claim
1. A flow measurement device having a tube or other container for receiving a flow of a liquid, a plurality of sensers associated with the container to sense when the liquid reaches a level in the container corresponding to each senser, and a timing device deriving a time difference between sensing of two levels, characterised in that there are more than two sensers and in that logic means associated with the timing device checks whether the time difference exceeds a predetermined minimum and if so calculates the flow rate from that time difference but if not inhibits that calculation and arranges for a time difference derived from a subsequent senser to be used in calculating flow rate.
1 Assignment
0 Petitions
Accused Products
Abstract
A flow measuring device for checking on medical infusion devices comprises a vertical tube 5 having at least three level sensers 10 and 11 for sensing when a liquid reaches the level of each senser. A logic unit 12 containing a timing device triggered by the first senser measures the time taken for the liquid to reach the second senser and the logic unit compares this time with a predetermined time and if the time is less than the predetermined time sets the device to compare a time taken to reach the third senser but if the time is more than the predetermimed time calculates the flow rate. A multiway valve 1 at the inlet of the device under the control of the logic unit permits flow from the infusion device under test to the tube, from the device under test to a drain 15 or to that drain and the tube, or from the tube to the drain or blocks all flows. The logic unit can sense an excessively rapid flow and treat the flow as a dummy run to be dumped without measurement and summon a subsequent flow to be measured. The tube can be linked to the drain by a pipe 14 so that measurement can take place against a back pressure. A succession of measurements are averaged.
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Citations
10 Claims
- 1. A flow measurement device having a tube or other container for receiving a flow of a liquid, a plurality of sensers associated with the container to sense when the liquid reaches a level in the container corresponding to each senser, and a timing device deriving a time difference between sensing of two levels, characterised in that there are more than two sensers and in that logic means associated with the timing device checks whether the time difference exceeds a predetermined minimum and if so calculates the flow rate from that time difference but if not inhibits that calculation and arranges for a time difference derived from a subsequent senser to be used in calculating flow rate.
Specification