Temperature measurement techniques

Temperature measurement is another important variable in any process industry. There have been several measuring techniques implemented in order to accurately measure this variable. These different techniques makes use of a variety of devices for measuring temperature. One of the most devices used from centuries till this day have been associated with fluids (like mercury or alcohol). The sole property of fluids to expand during high temperatures and vice versa, is the main reason for this association. However, there are some other instruments/devices which came to used at a later stage; namely, thermocouples, thermostats and resistive temperature devices (RTD) etc.

Resistive temperature detector (RTD)

As the name suggests resistive temperature detector, simply means a device which is used to detect temperature by detecting resistance.

Thermocouple operation

Thermocouple is an instrument used for measuring temperature in the form of voltage. It consists of two pieces of dissimilar metals with their ends joined together by methods such as twisting, soldering or welding. 

Three Valve Manifold

Three Valve Manifold:

     A three-valve manifold is a device that is used to ensure that the capsule will not be over-ranged. It also allows isolation of the transmitter from the process loop. It consists of two block valves - high pressure and low pressure block valve - and an equalizing valve.

Level and some of basic level measurement techniques

     After a few days of interval, starting with this post, in this article I'm about to decipher the basics of level and level measurement. Accurately measuring volume of  fluid in containers, continuously has always been a challenge in industries specially dealing with hazard environment, where the fluid could be acidic and/or may be maintained in high temperature/pressure. Considering these facts lets proceed to the article.

Some More Pressure Sensing Elements

     Most of the time the pressure to be measured and transmitted are built around the capsule concept, as seen in the previous blog-post. The capsules were capable of measuring mostly differential pressure (i.e., the difference between the high pressure input and the low pressure input) and thus they were called as differential pressure transmitter (DP Transmitter) or  DP cells.

Pressure And Sensing Elements

     In this post i'll try to cover the basics of pressure and the various principles associated with it. Pressure is probably most common measured variable in any industrial plant. it includes the measurement of steam pressure, feed water pressure, lubricating oil pressure, condenser pressure and many more.