When bandita was a little merchant marine engineer, she learned a lot about measuring quantities and magnitudes by reading all the different gauges used to monitor the equipment in the engine room. Unlike the imprecise people in the world, we don't feel that she wasted several mornings, a couple afternoons and an evening learning how to read different gauges and scales on the ship.
Thread pitch gauges are used as a reference tool in determining the pitch of a thread that is on a screw or in a tapped hole. This tool is not used as a precision measuring instrument. This device allows the user to determine the profile of the given thread and quickly categorize the thread by shape and pitch.
A U-tube manometer consists of a vertical column of liquid in a tube whose ends are exposed to different pressures. The column will rise or fall until its weight is in equilibrium with the pressure differential between the two ends of the tube. One side of the manometer is connected to the region of interest while atmospheric pressure is applied to the other. The difference in liquid level represents the applied pressure.
The Bourdon tube gauge is a nonliquid pressure measurement device. It is widely used in applications where inexpensive static pressure measurements are needed. A typical Bourdon tube contains a curved tube that is open to external pressure input on one end and is coupled mechanically to an indicating needle on the other end.
Vernier calipers can measure internal dimensions, external dimensions using the lower jaws, and depth measurements by the use of a probe that is attached to the movable head and slides along the center of the body. The vernier scales will often include both metric and Imperial measurements on the upper and lower part of the scale. Vernier calipers commonly used in industry provide a precision to one thousandth of an inch.
Pneumatic level sensors use the compression of a column of air against a diaphragm to actuate a switch, with no process liquid contacting the sensor's moving parts. These sensors are suitable for use with highly viscous liquids such as grease, as well as water-based and corrosive liquids. It has the additional benefit of being a relatively low cost technique for point level monitoring. These sensors tie into a digital readout at a central monitoring station.
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