Lesson 5 - Process Instrumentation SAQ

1.         * Make the following recommendations:

a)    Why should you use an ISFET pH sensor instead of a glass sensor?

b)    Why should you use an oscillating tube density meter and not a sound velocity density meter?

c)    When would you use manual instruments instead of electronic instruments?

2.         * Explain how you would use a point level switch and a continuous level transmitter. Give examples of where each would be used.

3.         * Answer the following questions:

a)    How does an RTD work?

b)    You have a temperature sensor installed on your wort line. It is imperative that you control temperature accurately. What specification of RTD would you make to ensure the accuracy you need?

4.          ** You need to measure the flowrate of wort at wort cooling, which is run at 100 hL/hr.

a) What are the factors that would influence your choice of instrumentation?

b) What process requirements should you contemplate and what are the accompanying financial considerations?

5.         ** You have three applications to measure: effluent discharge, the dilution liquor that is being produced in a deaerated liquor producing plant, and the wort leaving wort cooling as it goes into fermentation. You have three flowmeters available at the brewery: a magflow, a paddle turbine meter, and a Coriolis mass flow.

Which flowmeter would you use for each application? Explain the rationale for your choices.

6.         ** Your CIP tank (or scavenge tank) is giving an inaccurate level measurement. It is currently fitted with an ultrasonic level transmitter.

a)    Recommend the steps that should be taken to fix this problem.

b)    How would this be different if it was a bright beer tank and if this was your final product handover to packaging?

7.         ** How does a magflow work? Draw and label a diagram to show the principles.