Square Root Extractor Lab Report

The objective of this lab is to gain an understanding of the functions and characteristics of a Moore model 65 Square Root Extractor such as the principles of operation, calibration of the instrument, and its use in industry.
Principles of Operation: For this lab I worked with a Moore model 65 Square Root Extractor. The extractor works by taking in the pneumatic signals of differential flow transmitters and providing a linear output so the signals can be added, subtracted, averaged, or when the signals need to be linear to provide a proper representation for a control loop. The Extractor uses the cosine function of a small angle to give square root conversion. The angle is created by a continuous balance between the motion of the input pressure

Connect a variable input supply pressure to the square root extractor. Set a gage or pressure calibrator to measure the output of the Extractor For a standard input and output range of 3-15 psi first adjust the zero by inputting 3.12 psi to the extractor, at this point the output should read 4.2 psi. If 4.2 psi is not read turn the zero screw in to lower output pressure or turn the zero screw out to raise the output

Now adjust the input pressure to 15 psi at this point the output should read 15 psi. If the readings are not correct then adjust the span lever to the right to lower span or to the left to raise span until the values are correct. Repeat steps 4-6 until no further adjustments must be made. Preform a full scale reading at 0%, 10%, 30%, 50%, 70%, 90%, and 100% of span to ensure that the instrument has been properly calibrated throughout the span.
Use in Industry: Square root extractors are typically used in conjunction with a differential pressure transmitter that measures the differential pressure in a flow line pipe using an orifice plate, annular pipe, or venturi tube to determine the rate of flow through the pipe since flow rate is equal to the square root of the differential pressure measurement. This function is useful in any industry where flow rate measurement is required for process control and where pneumatic instruments are ideal such as in an explosive gas environment.
Conclusion:
Through the course of this lab I gained my first experiences with a square root extractor converting an input pressure value to its square root value. I found the calibration to be more complicated than most and difficult at times. I learned a vast amount of information and found it very