COMBINED GAS MICROFLOWMETER AND POTENTIOMETRIC SENSOR

A gas microflowmeter based on a potentiometric chemical sensor is demo nstrated. The flowmeter operates on the hot-wire principle, Electric c urrent is passed through a platinum microbridge. A preset bridge resis tance is kept constant by regulating the heating current. By measuring the changes in the heating current, the calibration flow curve can be obtained. The temperature profiles of both the electrically heated mi crobridge and the substrate in its vicinity, measured with an infrared microscope, are presented.