Abstract: A real time nonvolatile residue (NVR) monitor operates to efficiently detect molecular contamination in a given environment. The present NVR monitor utilizes surface acoustic wave (SAW) resonators in a controlled environment which efficiently promotes deposition of NVR on the sensor surface. The SAW resonators preferably operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10−11 g-cm−2 to 10−13 g-cm−2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency and to thermally separate NVR from a sample fluid contacting the SAW. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a preset temperature in accordance with optimal environmental conditions for separating NVR from the sample fluid.

Abstract: A real time non-volatile residue (NVR) monitor, which utilizes surface acoustic wave (SAW) resonators to detect molecular contamination in a given environment. The SAW resonators operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10.sup.-11 g-cm.sup.-2 to 10.sup.-13 g-cm.sup.2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a present temperature independent of the environmental conditions. In order to enable the direct heating and cooling of the SAW resonators, the SAW resonators are operatively mounted to a heat sink.