Silicone Rubber Heater for Blood Clot Sensing and Recording Instrument


Detecting and timing blood clotting is necessary for detecting defects such as hemophilia, diagnosis of clotting times for patients receiving anticoagulant drugs and pre-surgical examinations. Reagents used in the tests and blood plasma need warming and their temperature controlled to permit rapid and accurate processing.


Two Watlow silicone rubber heaters per heating block are used to heat reagents and to incubate the blood plasma.

Initially, Watlow was asked to provide a one square inch heater with high resistance and a hole in the center. The product manager recommended factory vulcanizing the two heaters to the customer furnished part This achieved a more efficient heat transfer and reduced customer installation costs. To reduce resistance, the hole was eliminated from one heater and both heaters were wired in series. The heater is die cut to reduce the cost of repeatedly meeting close tolerances of the contoured shape.