Abstract: A test device for a thermally-activated instrument so that the accuracy of the instrument can be determined. In a first form of the invention, a cylindrical enclosure is provided for retaining the instrument and is connected to a power supply via terminals attached to the enclosure. The enclosure is slotted along its length to permit enlargement of the enclosure when necessary. A second enclosure, also slotted along its length and with a temperature sensing thermocouple attached thereto, is provided for retaining the thermally-activated instrument and is shaped to fit within the first enclosure. In a second form, a series of clustered enclosures are provided, with the enclosures being of varying sizes to accommodate thermally-activated instruments of various sizes. In a third form, enclosures are grouped into at least two separate groups, with the groups being capable of being electrically interconnected.

Abstract: To provide a low cost electrical readout for differential fluid pressure, a strain gauge, preferably a piezo-resistive semiconductor, is bonded to a flexible strip of metal sandwiched diametrically between a matched pair of diaphragms circumferentially sealed in a fluid-tight cavity, preferably formed by a pair of modified orifice plates. Opposite sides of the diaphragm assembly are in fluid communication via suitable tubing with a fluid restrictive device, formed in one embodiment by a vane-type flowmeter. An inlet and outlet formed in each orifice plate allows shunted fluid to flow across opposite faces of the diaphragm assembly so that the semiconductor strain gauge can be used to sense the temperature of the fluid in the conduit. Replaceable inserts in the face of each orifice plate permit simple alteration of the device to meet desired operational parameters.