There is a flat silicone rubber membrane, or balloon, covering the pressure sensing diaphragm. Two internal tubes connect the two sides of the diaphragm to a female luer fitting on the connector shell. By introducing approximately 0.2 to 0.3ml of air, the pressure in these tubes will be greater than the ICP being measured. The exact amount of air is not critical, subject to the permitted maximum. When this air is injected, the pressure will cause the balloon to be lifted from the surface of the sensor and the same pressure will be applied to the back of the sensor. The strain gauge senses equal pressure above and below which is equivalent to having zero pressure applied. Thus by injecting a small volume of air, one undeflects the pressure sensor and checks the zero of the transducer and amplifier.
Sterilisation is by means of cold aqueous solutions of detergicide (e.g. Cidex) or by ethylene oxide gas. Do not use sodium hypochlorite solution.
Technical details:
Titanium 2.3mm thick 6mm wide
50cm silicone rubber 2.4mm Ø
Metal diaphragm with directly deposited resistive strain gauges
5V AC r.m.s. maximum or 1V DC maximum
Compensated temperature range:
Temperature coefficient of zero:
Temperature coefficient of sensitivity:
Linearity and hysteresis error:
Maximum balloon inflation volume: