Evaluation Essay

1423 words - 6 pages

For a process to be adequately controlled and manipulated, the variable of interest in the process (e.g. Temperature, Pressure or Flow) often called the Process Variable (PV) needs to be measured by a sensor which converts the measurement into a suitable signal format (4 – 20mA or digital) and then transmit it to a controller which makes the control decision and finally acts on a final control element in the control loop. What does this signal transmission is referred to as a transmitter. The schematic below illustrates the interactions between all the elements in the control loop:

Elements of a Process Control Loop |

What is a Transmitter?
A Transmitter is a device that ...view middle of the document...

3psig corresponds to the lower range value (LRV) and 15psig corresponds to the upper range value (URV). It is still commonly used today especially in remote locations where electric power is not readily available.
The invention of electronic instruments in the later part of the twentieth century significantly brought down the costs involved in running electrical signal wire through a plant as opposed to running pressurized air tubes. This has made the pneumatic signal technology less popular.

As shown below, a pneumatic pressure transmitter is supplied with air pressure typically 20 – 30 psig depending on the application. Process pressure is applied to the High port of the transmitter. As the process pressure varies, the transmitter produces an output signal (3 -15psig) that is proportional to the process pressure.

Pneumatic Type Pressure Transmitter |

Analog Transmitters
Analog transmitters are mostly electronic in nature. They output an electrical signal (current or voltage) whose magnitude represents a physical measurement or a control quantity. The transmitter is classified as being analog by virtue of the fact that it uses an analog signal standard to communicate information. The most common standard for transmitting an analog signal is the 4-20 mA current signal. With this signal, a transmitter sends a small current, proportional to the physical measurement, through a set of wires. In this signal standard, 4mA represents the lowest possible measurement or the LRV (Lower Range Value) while the 20mA represents the highest possible measurement or URV (Upper Range Value).
As shown below, the transmitter produces an output signal of 4 – 20mA when the process variable is applied to the transmitter:

Analog Transmitter |

Digital Transmitters
Digital transmitters produce digital signals that are combined in a variety of ways to enhance communication with the devices; enhances diagnostic capabilities of the device and makes control of the devices and processes relatively easy and smooth. Digital signals are discrete levels or values that are combined in specific ways to represent process variables and also carry other important information, such as diagnostic information. Digital transmitters combine the digital signals in a variety of ways leading to various communication protocols such as Fieldbus, HART etc.

Most digital transmitters may be referred to as smart instruments. They have inbuilt microprocessors that helps in signal conditioning and processing and gives the devices some diagnostic capability.

Electronic Transmitters
Electronic transmitters can be grouped according to the number of wires necessary to provide transmitter power. Accordingly, there are 2-wire, 3-wire and 4-wire transmitters. Please see Electronic Transmitters Wire Configuration for more details on transmitter wire configuration.

Transmitters Used in Process Instrumentation
In the process industries, there four...

Other Essays Like Evaluation

Allianz Evaluation Essay

3605 words - 15 pages * Contents 1. Executive Summary 3 2. Analysis Model 3 3. Company Overview 3 4. Industry Outlook 3 5. Company Evaluation 4 Free Cash Flow Estimation 4 Cost of Equity, Cost of Debt, WACC Calculation 5 Discounted Cash Flows and Company Evaluation 5 6. Sensitivity Analysis 6 7. Final Recommendations 6 8. Appendix 7 Appendix 1: Historical Free Cash Flow Analysis 7 Appendix 2: Historical Free Cash Flow Analysis 8

Community Evaluation Essay

730 words - 3 pages Community Evaluation Community Evaluation The purpose of this essay is to compare the similarities and differences between five different communities. Represented are Bland County, Virginia, Cedar Rapids, Iowa, Dunedin, Florida, Rio Vista, California, and Washington, D.C. The definition of community according to Bartle (2012) is, “The concept of community is a set of interactions, human behaviors that have meaning and expectations

Self Evaluation

661 words - 3 pages      Self-evaluation is definitely the most difficult type of criticism to receive. When you are hearing your faults from other people they usually go in one ear and out the other, but when you take a step back and realize for yourself that something needs to be changed within your personality, is it when you truly do something about it. I have a problem with allowing myself to become attached to girls that I have

Comfarmative Evaluation

683 words - 3 pages Confirmative Evaluation Plan Mekky Research literature throughout the past decade has shown that technology can enhance literacy development, impact language acquisition, provide greater access to information, support learning, motivate students, and enhance their self-esteem (ACT, 2004; CEO Forum, 2001; Boster et al., 2004; Mann et al., 1999; Tracey & Young, 2006; WestEd, 2002). Indeed, researchers have affirmed that computer

Motivation Evaluation

575 words - 3 pages Motivation Evaluation Michael Sanchez PSY/230 11/13/11 Patsy Giero Silva is a Brazilian mixed martial artist; Silva currently competes in the Light Heavyweight division for the Ultimate Fighting Championships. Silva was expected to face the former light heavyweight champion Quinton Jackson on May 28, 2011 at UFC 130, although there were rumors that the fight had been canceled due to injury or failed drug tests from his UFC 125 bout. In

Iphone5 Evaluation

1237 words - 5 pages XU1 Yuan Xu (Wish) Evaluation People use phones to contact each other, and the series of phones are changing a lot as time goes by. At first, we have phones need to transit by a station. Then we have telephones at home. Now we have mobile phones. There are lots of series mobile phones in our life. People may familiar with the smart phones. The smart phones can do much more than normal mobile phones. This evaluation is about one of the

Argument Evaluation

760 words - 4 pages Nicole P. Harrell-Lockhart November 6, 2011 Argument Evaluation Argument number 1 We might have accomplished if we had been a treat terrorist attacks of 9/11 in a way similar to how we treat the carnage on the nation’s highways by implementing practices and requirements that are directly related to results (as in the case of

Othello Evaluation

988 words - 4 pages Othello Evaluation 1. “Iago as a triumphant villain” By W.H Auden The main Idea for this essay is that Iago as a villain succeeded in everything he intended to do. This essay talks about how a single person performs all the actions. They refer to Iago as almost like a hero in their opinion he was triumphant and like most villains could not be made fun of because the things he does is so real. I would have to agree I believe Iago was a

Country Evaluation

969 words - 4 pages Peru: Country Evaluation Geographical Situation Peru is located in the west of South America, and has borders with Ecuador, Colombia, Brazil, and Chile. It is almost twice the size of Texas. Peru is the third largest country in South America, and has a wide range of natural resources. The country has three main regions which are coast, mountains and jungle (Peru Travel, 2015). Generally, May through October is the dry season; November through

Evaluation Table

850 words - 4 pages utilize it daily. Further benefit can be gained by education of suppliers and external customers. Inclusion of this information on a monthly basis for discussion would further the visibility of discrimination, both intentional and non-intentional and breed a venue for trust, discussion, and openness that would enlighten all involved and bring the work group into a cohesive unit. Research Evaluation My organization would benefit from this study


1349 words - 6 pages Week 7 Individual Work Jamie Jones Everest Online David Goldberg Week 7 Individual Work “Writing in his journal on July 25, 1945, President Truman described with utter clarity his views on the destructive nature of the atomic bomb: We have discovered the most terrible bomb in the history of the world. It may be the fire of destruction prophesied in the Euphrates Valley era, after Noah and his fabulous ark. Yet, despite his characterization

Related Papers

Scenario Evaluation Essay

752 words - 4 pages Scenario Evaluation Plan Holly Regan HSM/270 June 20, 2014 Fedder Williams Scenario Evaluation Plan PEACE Domestic Violence Agency’s main purpose is to provide victim support and shelter, victim advocacy and education, and empower those who are directly or indirectly affected by domestic violence. To continue helping the many who suffer from domestic abuse, PEACE Domestic Violence Agency will develop an evaluation plan to assess the

Job Evaluation Essay

561 words - 3 pages Job Evaluation Method: The essence of compensation administration is job evaluation and the establishment of the pay structure. Let’s now turn our attention to the topic of job evaluation. By job evaluation we mean using the information in job analysis to systematically determine the value of each job in relation to all jobs within the organization. In short, job evaluation seeks to rank all the jobs in the organization and place them in a

Tender Evaluation Essay

1140 words - 5 pages EVALUATION REPORT FOR THE RENOVATION OF VACANT HOUSES FOR REAL ESTATE DEPARTMENT, AKOSOMBO 1.0 INTRODUCTION VRA has allocated funds as part of its budgetary allocation to cover the cost of renovating staff houses. Real Estate Department intends to apply these funds to cover eligible payments under the contract for the renovation of vacant houses at Akosombo. 2.0 TENDERING PROCESS Price quotation method was used to source for the

Character Evaluation Essay

587 words - 3 pages 1 Check Point: Character Evaluation PYS/230 8/19/13 Diane Pascoe 2 Introduction “The big five dispositional traits are as follows, extraversion, neuroticism, openness to experience, agreeableness, and conscientious.” (McAdams, D. 2009. p. 85.) Character evaluation is a basic break down of one’s personality and how their traits come together. Behavior is a huge concept to one’s personality and how they act in certain situations. In