Liquid Level Measurement Part 1

Topic I: Principles of Level Measurement Determine whether the system measures innage or outage (ullage) Determine whether the liquid containers have uniform or nonuniform cross-sections Determine whether the container is open or closed Determine whether the system is a continuous level measurement system or a single-point level detection system Topic II: Simple Level Measuring Instruments Read or compute the indicated level for the following simple level measuring instruments: Dipstick Gauge stick Plumb bob (for innage and outage measurements) Gauge glass Topic III: Floats and Displacers Read the indicated level determine whether the reading is a true indication of level and if it is not troubleshoot and repair the instrument for the following float-actuated instruments: Float and calibrated rod (or mechanical linkage) Float tape (or chain) and counterweight Float cable and pulley (with/without winder window) Given a level control diagram and a gauge stick troubleshoot a problem with a sump pump when the pump is controlled by a ball float and a mechanical float switch. List the major parts of a typical torque-tube displacer and explain the function of each part. Topic IV: Magnetic Float Devices Read the indicated level on a magnetic float-actuated device that uses a floating magnet and a follower magnet. Troubleshoot the system if controls are not actuated at specific levels in the tank for the following magnetic float-actuated devices: A system that uses reed switches A system that uses a ball float and mercury switches Topic V: Conductance and Capacitance Probes Describe what happens in the control circuit of a conductance probe system when level increases and when level decreases. Be able to safely perform maintenance on the probes for a level measurement system that uses conductance probes. Describe the relationship between capacitance and changes in level in a level measurement system that uses capacitance probes. Topic VI: Sonic and Nuclear Radiation Instruments Describe the use of sound waves in a continuous level measurement system and in a single-point level detection system Describe how radiation is used in a continuous level measurement system and in a single-point level detection system.