Electronic Maintenance

This comprehensive INVOLVE® multimedia training program was produced in association with the Instrument Society of America (ISA). This five lesson program trains participants in Me maintenance of electronic instruments, including pressure, temperature, flow, level, and weight transmitters as well as transducers, recorders, annunciators, and analog electronic controllers.

Audience: This program is excellent for training for maintenance personnel and instrument technicians as well as for the multi‑craft training needs of process and manufacturing facilities.

Pressure and Temperature Transmitters


Prerequisites: This program is designed for participants familiar with process and control principles as well as basics of digital electronic theory and test procedures.

Description: This lesson introduces electronic transmitter maintenance focusing on pressure and temperature transmitters. The lesson describes the components of a typical pressure or temperature transmitter, their functions, adjustments, inspections, and repairs. Procedures for isolating the faulty component in a transmitter are also demonstrated.

Objectives:

  • Identify components in a disassembled electronic differential pressure or electronic temperature transmitter
  • Test the power supply for the transmitter in an electronic pressure transmitter
  • Adjust the sensor zero and replace the electronics module of the pressure transmitter
  • Isolate malfunctions to either the sensor or circuitry portion of a differential pressure transmitter
  • Verify that a sensor is properly grounded
  • Swap circuit boards in a differential pressure transmitter
  • Replace the sensor assembly of a DP transmitter
  • Identify the faulty component in a thermocouple transmitter
  • Test outputs and repair an RTD
  • Swap a defective board to calibrate a malfunctioning RTD

Flow Transmitters


Prerequisites: This lesson is designed for participants familiar with electronic test procedures. An understanding of process operation is also required.

Description: This lesson introduces the inspection and repair of electronic flowmeters by demonstrating maintenance procedures for vortex shedding, turbine, magnetic, and mass electronic flowmeters. The lesson describes typical flow transmitter components, their functions, common malfunctions, and procedures for isolating a faulty component.

Objectives:

  • Test and replace the amplifier unit, sensor, and bluff body of a vortex shedding flowmeter
  • Test and replace
  • The preamplifier unit, coil and other necessary components of a turbine flowmeter
  • Test and replace the coil, electrodes, and circuit board in a magnetic flowmeter
  • Jumper the appropriate terminals to simulate zero output and check the flowmeter output in an installed mass flowmeter
  • Test and replace the sensor and circuit boards in an installed mass flowmeter

Level and Weight Transmitters


Prerequisites: This lesson is designed for participants familiar with basic mathematical operations including algebra.

Description: This lesson describes the operation, applications, and maintenance of ultrasonic, capacitance, conductivity, and radiation level detectors. The lesson also explains the functions and operation of weighing systems.

Objectives:

  • Describe the applications and operation of ultrasonic level detectors and their use in both point and continuous measurement applications
  • Troubleshoot and maintain ultrasonic level detection systems
  • Describe the applications and operation of radiation level detectors and their use in both point and continuous measurement applications
  • Explain the safety considerations when maintaining radiation level detectors
  • Describe the applications and operation of capacitance and conductivity level detectors in both point and continuous measurement applications
  • Recognize safety considerations for the use of level probes with flammable and/or explosive materials
  • Identify the maintenance procedures for capacitance level detection systems
  • Describe the applications and operation of a strain gage load cell as well as considerations for load cell calibration
  • Describe the applications and operation of a belt conveyor scale as well as how to test and calibrate it

Transducers, Recorders, and Annunciators


Prerequisites: This lesson is designed for participants familiar with calibration principles, process control, and control loops.

Description: This lesson teaches routine maintenance requirements and calibration procedures for transducers, recorders, and annunciators. The lesson provides a basic understanding of the functions of I/P, P/I, and E/I transducers, multipen and multipoint recorders, and annunciators. The lesson also outlines how to identify and troubleshoot problems in these instruments.

Objectives:

  • Identify and describe the function of electronic transducers
  • Identify how I/P transducers work
  • Identify troubleshooting steps for pneumatic and electronic function on I/P transducers
  • Identify the steps for continuity tests on I/P transducers
  • Identify coil replacement steps for I/P transducers
  • Identify calibration steps for P/I and E/I transducers, identify motor replacement steps for the chart drive on a multipen recorder
  • Identify the function of drive gears on a multipen recorder and how to clean them
  • Identify installation steps for a new drive cable on a multipoint recorder and check for proper operation
  • Identify the function of drive wire resistors on multipoint recorders and how to clean and inspect them
  • Calibrate multipen and multipoint recorders
  • Define the function of annunciators and troubleshoot them

Electronic Controllers


Prerequisites: This lesson is designed for participants familiar with process control and control loops.

Description: This lesson presents routine maintenance requirements and calibration procedures for electronic controllers. The lesson shows how controller circuitry works and how to adjust and calibrate each of its component sections: the display, the alarm circuitry, and the control circuitry.

Objectives:

  • Identify the features and functions of controllers
  • Describe and compare pneumatic and electronic controllers
  • Identify the signal path through a control circuit
  • Describe the function of resistors, comparators, proportional band amplifiers, integral amplifiers, differentiating amplifiers, summing amplifiers, and the transducer
  • Visually identify indicators on electronic controllers as well as set point, process, output, and alarms
  • Visually identify controls on electronic controllers as well as set point control, auto-manual selector switch, and manual/valve control
  • Identify appropriate equipment and demonstrate procedures for calibrating and troubleshooting display indicators
  • Identify appropriate test points and demonstrate procedures for calibrating and troubleshooting alarm indicators
  • Identify appropriate equipment for calibrating control circuits and calibrate proportional, integral, and derivative zero on the control circuit
  • Identify appropriate equipment for troubleshooting control circuits