ABSA 4th Class Part A Power Engineering - Instrumentation final review, A Guide

ABSA 4th Class Part A Power Engineering - Instrumentation final review, A GuideFlow is proportional to: Select one: a. the square root extractor b. pressure differential c. the square root of the temperature differential d. the square root of the pressure differential e. a constant head - d A capillary is the name given to: Select one: a. the bulb holding the fluid of a filled thermometer b. the line attached to the measuring junction of a thermocouple c. a tube with a small uniform bore d. the key part of a thermistor e. a unit used only in refrigeration - c Thermo wells are: Select one: a. Used in pipes only b. Not used with thermocouples c. Used to protect the bulb from erosion, corrosion and impact d. Used in conjunction with a capillary tube e. Made of soft material - c Which flowmeter has a ball-like structure with a small shaft in the centre? Select one: a. nutating disc b. rotary meter c. magnetic flowmeter d. target flowmeter e. rotameter - a Flow inside a pipeline can differ considerably. Normal flow is referred to as: Select one: a. transitional b. laminar c. segmental d. lunar e. turbulent - b What is not a characteristic of a radiation detector? Select one: a. radiation source is usually uranium b. high in cost with special handling requirements c. needs a lead-lined stainless steel container d. special precautions must be taken e. radiation received from the source is an indication of the level - a Another name for a variable area meter is: Select one: a. nutating disc b. pressurized bubbler c. atmospheric bubbler d. target flowmeter e. rotameter - e On a thermocouple the joined end is called the: Select one: a. proportional connection b. none of the answers c. measuring junction d. thermowell e. reference junction - c To get more rotation of a pointer, the bimetal strip would be made ----------. Select one: a. shorter b. in the form of a helix c. longer d. thicker e. thinner - b Which flowmeter gives the least pressure loss? Select one: a. Pitot tube b. orifice plate c. magnetic d. nutating disc e. target - c What can be used as a level indicator? Select one: a. differential pressure transmitter b. all of the answers c. capacitance probe d. diaphragm box e. bubbler - b A steam gauge which would be used on a portable boiler where external vibrations are common would be this type. Select one: a. double bourdon b. spiral c. bellows d. spiral, spring-mounted e. helix - a Bimetal thermometers depend on the principle that: Select one: a. oval-shaped objects will expand into a circular form b. dissimilar metals expand at different rates when heated c. similar metals contract at the same rate d. dissimilar metals can produce more power to move a needle e. none of the answers - b What is the most undesirable feature of an orifice plate? Select one: a. high permanent pressure loss b. high cost of installation c. long length of straight pipe needed d. high-corrosion rate e. special flanges needed - a A pressure-sensing instrument which is used for very low pressures up to + or - 250 mm of water is a: Select one: a. double helix gauge b. double tube bourdon gauge c. absolute pressure gauge d. barometer e. diaphragm - e A radiation pyrometer senses: Select one: a. color of a hot object b. intensity of heat radiation c. thermocouple signal d. energy from a hot object focused on a thermistor e. brightness of radiated light - b What can be added to a diaphragm to give it extra strength? Select one: a. leather b. thin metal disc c. plastic d. impregnated silk e. cotton-lined rubber - b Pitot tubes are used where: 1. temperature is not a concern 2. accuracy is not a prime concern 3. permanent pressure loss is intolerable 4. velocities are low Select one: a. 1, 2 b. 4 c. 2 d. 2, 3 e. 1 - d Can bourdon tube gauges be used for vacuum measurement? Select one: True False - True With an ultrasonic level detector, what does the receiver record so the level can be determined? Select one: a. decibel level b. temperature c. low level radio-waves d. time e. frequency - d Differential pressure meters measure flow by using some form of restriction to: Select one: a. B and D b. increase velocity c. increase pressure d. create a pressure drop e. decrease velocity - d What can be used as a level indicator?