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Test your knowledge with CCST ...

The following sample questions (not actual exam questions) appear in the Certified Control Systems Technician (CCST) Study Guide published by ISA.

CCST questions

1) What pressure, in psi, would be indicated by an absolute pressure gauge that is lying on a workbench not connected to anything? A. 0 B. 29 C. 14.7 D. 2.9

2) A gauge pressure of 195 psi is roughly what in psia? A. 151 B. 164 C. 178 D. 210

3) Which of the following will have the highest-pressure difference between the surface and 6 in below the surface? A. a 12-in vertical straw filled with water B. a 10-ft-diameter vertical pipe filled with water C. a 5-ft-diameter vertical pipe filled with water D. none of the above because the pressure difference in each is the same

CCST Answers

1) A gauge pressure of zero indicates the absolute pressure of the fluid is equal to atmospheric pressure. The relationship between absolute and gauge pressure is: Pabsolute=Pgauge+Patmospheric Atmospheric pressure is 14.7 pounds per square inch (psi). Thus, the correct answer is C.

2) Use the same relationship we used in No. 1 to solve this question. Pgauge (psig) is given here as 195.Patmospheric we know is 14.7 psi. Add these two numbers together to obtain Pabsolute (psia). The best answer is D.

3) Pressure is the ratio of a force to the area on which the force acts: P=F/A. Since the fluid is the same and the distance under the surface is the same, the weight (force) of the fluid and the pressure difference is also the same. The correct answer is D. —Nicholas Sheble