Abstract: An object of the present invention is to provide an environment testing apparatus capable of achieving, on the surface of a test object, a stable condensation status with less variation in the condensation amount than that of already existing-art. The environment testing apparatus 100 includes a regulator 4. On the basis of a signal from a condensation amount sensor 9, the regulator 4 controls the temperature of a cooling/heating plate 6 between a deviation-added value of the wet bulb temperature obtained from the wet bulb 11, and a deviation-added value of the dew-point temperature inside the test chamber 1.

Abstract: An object of the present invention is to provide an environment testing apparatus capable of achieving, on the surface of a test object, a stable condensation status with less variation in the condensation amount than that of already existing-art. The environment testing apparatus 100 includes a regulator 4. On the basis of a signal from a condensation amount sensor 9, the regulator 4 controls the temperature of a cooling/heating plate 6 between a deviation-added value of the wet bulb temperature obtained from the wet bulb 11, and a deviation-added value of the dew-point temperature inside the test chamber 1.

Abstract: A probe for measuring the temperature and moisture of a gas has an aspirated flow passage with a configuration that causes the gas to have turbulent flow and, therefore, to mix. A dry bulb thermometer and a wet bulb thermometer positioned in the flow passage downstream of the configuration that causes mixing measures the temperature and moisture of the gas. A wick and a water reservoir for keeping the wet bulb thermometer wet are cleaned and refilled by a flow of water through the gas passage. The gas passage is heated to prevent condensation of any moisture in the gas.

Abstract: A method of detecting a dry/wet state of a thermistor bead comprises the steps of: conducting current through the thermistor bead selectively between first and second current levels; measuring a difference in voltage across the thermistor bead in response to the first and second current levels; and detecting the dry/wet state of the thermistor bead based on the measured difference in voltage. In one embodiment, the first and second current levels conducted through the thermistor bead are both less than thirty milliamps. Apparatus for embodying this detection method is also disclosed.

Abstract: A method of detecting a dry/wet state of a dual thermistor bead sensor over a wide operating temperature range comprises the steps of: conducting first and second predetermined currents through one and another of the thermistor beads of the sensor, respectively, the second predetermined current being substantially less than the first predetermined current; measuring a first voltage across the one thermistor bead in response to the first predetermined current and generating a first signal representative thereof; measuring a second voltage across the other thermistor bead in response to the second predetermined current and generating a second signal representative thereof; modifying the second signal by an offset and gain to generate a third signal; and detecting the dry/wet state of the sensor over the wide operating temperature range based on the first and third signals.

Abstract: A method of detecting a dry/wet state of a thermistor bead comprises the steps of: generating a current waveform that transitions between first and second current levels; conducting the current waveform through the thermistor bead; measuring a voltage waveform across the thermistor bead in response to the current waveform; measuring a slope of the voltage waveform in response to the first and second current levels and generating a first signal indicative of the measured slope; differentiating the voltage waveform to produce a voltage pulse representative of a transition of the voltage waveform from one voltage potential to another and generating a second signal indicative of the polarity of the voltage pulse; and detecting the dry/wet state of the thermistor bead based on the first and second signals. Apparatus for embodying this detection method is also disclosed.

Abstract: A sensor for sensing in a gas stream a vapor of a liquid. The sensor includes a micropore and a wet temperature sensor. The micropore has an evaporation end and has a lumen to conduct liquid from a supply of the liquid for evaporation at the evaporation end. The wet temperature sensor has a heat sensitive part in contact with the liquid in the micropore. The heat sensitive part circumscribes the micropore and forms part of the lumen. Heat loss due to evaporation of the liquid when the wet temperature sensor wet with the liquid is placed in the gas stream will result in the temperature sensed by the wet temperature sensor being lower than the non-evaporative temperature of the gas stream. This lowering in temperature can be measured to determine the concentration of the vapor in the gas stream. An example of such a sensor has a thermocouple junction having micropores passing through the thermocouple junction.

Abstract: An air tunnel device is provided for use in combination with a thermohygrter of the type where the change of resistance of the probe in response to changes in the ambient atmosphere is used to measure the temperature and humidity of the atmosphere. The device includes a housing which defines an air passageway therethrough, a probe support for mounting the probe of the thermohygrometer so that the probe is exposed to the air passagement in the housing and a fan mounted in the housing below the probe support for drawing air into the air passageway and thus providing air flow at a constant velocity past the probe.

Abstract: The invention relates to thin silicon membranes formed in layers of silicon such as are normally utilized as substrates in the manufacture of integrated electronic circuits. The thin membranes constructed in accordance with the invention are capable of deformation by electrostatic forces and are applicable to a wide range of uses including the manufacture of solid state pressure sensors, resonant, and antenna structures, as well as electro-optical display elements. A processing technique is disclosed which is particularly adapted to forming membranes in silicon substrates in a manner which is compatible with the construction thereon of other integrated circuit components.

Abstract: Apparatus for measuring and controlling the relative humidity of exhaust air from an industrial drier in which exhaust air is passed across a dry bulb and a wet bulb thermocouple from which a voltage is derived providing a measure of the relative humidity in the air in the sample. This voltage is used to control the amount of exhaust air from the drier to atmosphere. The wet bulb thermocouple is cyclically dipped in a bowl of water under the control of a timer system of the voltage to control the amount of exhaust air discharged until the wet bulb thermocouple is equilibrated with the exhaust air sampled after dipping.