Lesson Plan. ER Pressure. Calibrating Differential Pressure Transmitters

Transcription

1 Lesson Plan ER Pressure Calibrating Differential Pressure Transmitters College of the North Atlantic Electrical Apprenticeship Training 1

2 Course Outline for ER 2152A Calibration of a Differential Pressure Transmitter Facilitator: Paul Wakeham Contact: College of the North Atlantic Seal Cove Campus CBN Telephone: paul.wakeham@cna.nl.ca Calendar Description: Upon successful completion of this unit of instruction, the apprentice will be able to calibrate differential pressure transmitters for industrial process applications. Course Prerequisites: Completion of block four electrical apprenticeship courses Students: Those who have been identified by the Department of Industrial Training as Industrial Electrical Apprentices who have completed training up to and including Block IV Industrial Electrical Courses and have the required workplace experiences. Goals: Develop knowledge, skills and attitudes necessary for journeyman industrial electricians to install, maintain and troubleshoot systems involving monitoring and control of electronic and pneumatic pressure transmitters. Rational: Manufacturing industries utilize electronic and pneumatic control for most processes. An understanding of the mechanical variables and their measurement methods is a requirement for today's electrical personal. Application and maintenance of the electrical/pneumatic monitoring and control for these systems is part of the daily routine for the industrial electrician. One of the most important tasks is troubleshooting and maintaining transmitters by using very specific calibration techniques. Course Duration: 8 Hours Introductions, Overview of objectives, pass out materials: One Hour Learners read text information, complete and check self-text: One Hour Break: One-Third Hour Power point presentation c/w video and link to manufacture: One Hour Solve formulas and review in class: Two Thirds Hour Lab; Read procedure, set up, complete lab and cleans area. Three Hours Class review of lab findings: One Third Hour Write test, Correct and review results: Two Thirds Hour Location: Instruction and testing: Classroom with internet connection Lab procedure: Instrumentation lab 2

3 Course Outline for ER 2152A Calibration of a Differential Pressure Transmitter 1.0 Resources: 1.1 Process Control Series # 773, Pressure Measurement, Section Lab: Calibration of a Pressure Transmitter 1.3 Power Point Presentation 2.0 Exam: Multiple-choice general knowledge questions Draw and label lab procedure diagram 3.0 Evaluation: Lab Experiment: 60 % of Final Mark Exam 40 % of Final Mark 4.0 Suggested Duration: 8 hours 5.0 Course Topics: 1.1 Transmitter Inputs 1.2 Transmitter outputs 1.3 Pressure Measurement with Transmitters 1.4 Lab Procedure for calibration or Troubleshooting 1.5. Documentation of calibration as found and as left status 6.0 General Objectives for Pressure: Upon successful completion of Transmitter Calibration the apprentice will be able to: 1. Explain reasons for calibrating transmitters 2. Demonstrate ability to calibrate linier output transmitters 7.0 Learning Objectives: 1. Demonstrate converting transmitter input signals to output signals 2. Follow lab procedure without guidance to perform transmitter calibration 3. Document transmitter nameplate data 8.0 Materials and Media: Text readings, Diagrams, Formulas, Lab Experiments, Power Point Presentation 9.0 Extent of Learning: The formula to convert input signals to output signals for proportional transmitters will be stated. The formula for converting the various types of signals will be stated. A pressure signal and a stated range calibration will be determined by applying known input pressures. Transmitter as found and as calibrated documentation will be completed. 3

4 Content Learner Response Resource/Media Introduction of self to the class and introduction of students to facilitator/classmates Each learner will respond with their name and reason for attending Introductory welcome Introduction to the course with an overview of the general objectives Text Information Text Self-test Power Point Presentation Introduce Transmitter with photo Ask learners if anyone has any experience with pressure transmitters Present Learning Objectives Read out objectives and gage audience responses to ensure they understand Overview of Operation The transmitter receives a pressure signal from a process. This pressurizes a peizo electric crystal The crystal outputs an electric millivolt signal that is proportional to the input pressure The electric signal is converted to a useable 4 20 milliamp output signal The % input = the % output Learners will read objectives to ensure they know what is expected of them upon completion of the course The student will study the text information; section 5, pages 65 to 72 Learners will complete the self test and check self-test answers Learners will participate in the demonstration Learners respond with experiences Learners read each objective and ask questions if necessary Course outline c/w general objectives Pressure Measurement # 773 Section 5 Pressure Measurement # 773 Section 5 self-test answer key Laptop, Media Projector, Internet Connection, Power Point Slides, notes Power Point Slide #1 Power Point Slide #2 Power Point Slide #3 Prop cutaway of a pressure transmitter for demonstration 4

5 Introduce conversion formula Output = %Span x Span + LRV Learners will use the formula to calculate answers Power Point slide #4 Output =.75 x (20 4) + 4 Output = 8 milliamp Use formula for a 60% input Answer: Output =.6 x Output = 13.6 milliamp Power Point Presentation regarding Transmitter Data The model and serial number must be documented each time a calibration procedure is performed The Range (Working Parameters) The Maximum Working Pressure ((Process Maximum) Power Point Presentation regarding Manufacture s data The transmitter we will be using in our lab procedure is a range code 3. Power Point Presentation regarding calibration data sheet Instruct details of each box to be filled in. - Transmitter date - Test equipment data - As found section - As left section Learners to make notes on this important procedure Learners will use manufactures data to note range code three pressure upper range value. Learners will study layout of the sheet to note data information area Power Point Presentation Slides 5,6,7 & 8 Power point Slide # 9 Link to manufactures pdf Specification Range code three: 30 inh2o Power Point Slide # 10 Pass out blank calibration sheet for each learner. Power Point Video of lab familiarization Learners will watch the video Power Point Slide #11 Video of lab calibration procedures 5

6 Lab Experiment Repeat points learned in the lab experiment. Students will participate in the lab (two per station) The formula will be used to determine calibration pressures and expected results. Learners will follow the procedure and document results. All tools and equipment to be returned to the shelf and the area cleaned. Learners will share lab experience with the class Lab Lab equipment: pneumatic pump, electronic manometer, 0 15 PSI gauge, Range 3 Transmitter, Fittings and tubing, Ammeter, Electrical wiring. Summary slide # 12 Oral questions regarding the lab experiment asked to the class Why must a transmitter that has been removed from service always have as found calibration documentation completed? Why are transmitted signals lower range values always at a value higher than zero? Why can a 4-20 ma signal be sent longer distances than a 3-15 PSI signal? How could you use a pressure transmitter to automatically control the level of the water in a town s water tower? If you knew the level of the liquid in a tank could you use a pressure transmitter to determine the liquid s specific gravity? Test presented to the learners. Note: Twenty minute time limit Learners will consider the question and take part in class discussion. Learners will complete the test List of possible answers to oral questions. One copy of the test for each learner. One answer key One test score document 6

7 ER 2152 Pressure: Sample exam questions 1. A linier potential potentiometer is a device which converts motion into: K1 a. A proportional pneumatic signal b. A proportional electrical signal c. A proportional resistance signal d. A proportional current signal 2. A bourdon tube pressure gauge has a scale of 0 to 250 PSI and an accuracy of +/- 1% of span. If the gauge reads 175 PSI, what will be the maximum correct pressure? K2 a PSI b PSI c PSI d PSI 3. A 3 15 PSI pneumatic pressure transmitter is calibrated for a pressure range of 100 to 500 PSI. The signal output is 11.2 PSI. What is the measured pressure in PSI? K3 a PSI b PSI c PSI d PSI 4. An elastic element that is a flexible chamber with accordion walls: K1 a. Pressure element b. Diaphragm c. Bellows d. Manometer 5. A pressure recorder attached to the bottom of an open tank reads 28 PSI and a barometer reads inches of mercury. What is the absolute pressure? K4 a PSI b PSI c PSI d PSI 6. Draw the connection diagram used with your lab procedure for calibrating a D/P transmitter. Use ISA symbols for devices and transmission lines. Use a pencil and ruler; neatness counts. P2 Answer: Use drawing from lab experiment. 7