A Guide For Selecting Industrial Transmitters For Manufacturing Industry

In terms of pressure and temperature, the industrial transmitters are types of electronic devices, that are designed to provide accurate measurements. The usage of transmitters allows for the monitoring and control of applications, thus ensuring stability, reliability, and safety of processes. Moreover, the industrial transmitters are designed  with additional reset and calibration options. This would allow the transmitters to adjust the measurement range while ensuring a complete output signal. Depending on the process application, the transmitters can be segregated in several types. The transmitters are broadly divided into three groups- type, signal production, and process instrumentation. The industrial transmitters can be divided into the following products, based on these groups-

  •  Electronic: Subdivided into two types i.e. Analog and digital
  •  Pneumatic

The industrial transmitters mentioned above are those classified as broad types and signal production, whereas the transmitters that are utilized for process instrumentation purposes are four types. All the transmitters have multiple common types that are used for various industrial applications.

  • Flow - ultrasonic flow sensors, differential pressure flow sensors, and velocity flow sensors
  • Temperature - Thermocouple type, RTD Type
  • Pressure - Absolute Transmitter, Gauge Transmitter, Differential Transmitter
  • Level - Point Level, Continuous Level, Ultrasonic Level, Conductive Level, Pneumatic Level, Capacitance Level, Hydrostatic based


Why Use A Flow Transmitter?

With a flow transmitter, one can measure and indicate flow. The flow sensor and transmitter are combined in one piece. The changes in flow in the actual process are represented by the flow signal from the flow sensor that is utilized by the transmitter to generate a 4-20mA output. Many customers often just want to know the rate at which a gas or liquid is flowing through a pipeline. In such cases, a simple flow indicator available at a fraction of the cost of the simplest flowmeter will usually suffice. These instruments are simple and easy to install. It requires no external power and can be used to provide local indication of flow.

How To Select/Choose A Flow Transmitter?

When it comes to selecting or choosing a flow meter, the cheapest is by no means best. Even though, it might seem the best way to save money in the short term, considering the lower cost solution may potentially result in problems later down the line. The most-effective installation will be the one where the supplier can provide good technical back-up, an established track record, independently traceable test facilities, and a reputation for high-reliability products based on development and sound-research. There are a few considerations when selecting a flow meter.

A) Purpose and application of the flow meter - What exactly do you want the flow meter to accomplish? What are the requirements of the job at hand? What is the application type?

B) Flow profile of the flow meter - What are the flow rates and characteristics of the liquids or gases for your application? Have you identified the minimum and maximum flow rates for your application? What do you know about the performance qualities of the specific flow meter?

C) Flowmeter performance and capabilities - What size flow meter will be sufficient for your needs? Does the flow meter material or construction have any impact on the fluids of gases that you are moving to? What about the pressure and temperature of the fluids and gas - how will that affect the performance of the flow meter or accuracy of measurement?

D) External factors - What real-life conditions may contribute to equipment downtime? Are their local environment or government regulations that might affect your operations? What about vendor selection?

E) Budget - What is the cost of the flow meter and related equipment? What about installation and maintenance costs? What are the costs of operations? Have you considered the expected lifespan of the flow meter or depreciation values?

What Are The Different Types Of Flow Transmitters?

To measure the flow, various technologies are used in flow transmitters. These include ultrasonic flow sensors, velocity flow sensors, and differential pressure flow sensors.


Why Use A Temperature Transmitter?

Temperature transmitters convert the thermocouple or Resistance Temperature Detector (RTD) signal to a 4-20 mA output signal and are the ultimate solution for many remote temperature measurement applications. Moreover, 4-20 mA transmitters have specific advantages over conventional temperature measuring devices. However, it must be selected with caution to avoid "ground loop" problems. The temperature of a remote process must be monitored in many cases. The common sensing devices such as the thermocouples and RTD's produce very fewer signals. A two-wire transmitter would be connected to these sensors that will amplify and condition the small signal. This signal can be transmitted through ordinary copper wire once conditioned to a usable level, and used to drive other equipment such as data loggers, computers or controllers, meters, and chart recorders.

How To Select/Choose A Temperature Transmitter?

When selecting a temperature sensor, there are several considerations.

A) Type of application - What is the device to be measured? Is there ambient temperature in a room or enclosure? Is it an electronic component with plastic or metal packaging that may or may not have high voltages present? Or a bulk of glowing steel? Maybe some parts of an automobile engine such as exhaust port or an intake?

B) Range of expected measured temperature - What process are we measuring the temperature? When exactly should you use an RTD or a thermocouple? Are there applications where a thermocouple is more suitable than an RTD or vice versa? Does the accuracy level of application determine which sensor to use? What could be the ambient temperature range around the measurement point?

C) Temperature display - Is It desirable to have a local display of the temperature? Are you monitoring temperature trend or an actual controlled valve? What is the temperature range of the application? What is the control point? What is the maximum and minimum temperature required for the application?

D) Temperature sensor type - Do you have an established plant or company preferences that may influence your choice of temperature sensor? Are there any specific temperature senor types in your inventory? What is the stability and control precision requirement? Any particular speed of response to the temperature change requirement?

E) Costs and Safety Concerns - What costs are associated with temperature management failure? Is the temperature measurement part of the Safety Instrumented System?

What Are The Different Types Of Temperature Transmitters?

Different types of transmitters utilizing various temperature measurement technologies are available to be used in the process industries. The most common types include thermocouple type temperature transmitter and RTD type temperature transmitter.


Why Use A Pressure Transmitter?

With pressure transmitters, the low-level electrical outputs from pressure-sensing elements are converted to higher-level signals that can be transmitted over a long distance for further processing and usage in various systems. A pressure transmitter has been designed to measure pressure in liquids, fluids, or gases. And for this, various sensing technologies have been utilized. The main purpose of deploying a pressure transmitter is to measure the pressure transmitter of different points of interest and to express the values in different units.

How To Select/Choose A Pressure Transmitter?

Selecting an appropriate pressure transmitter for a correct application can be a tedious task and failure to do so can make the operation of the equipment ineffective and possibly risky. The operating conditions (environment) and performance requirements are the two primary areas to focus on when selecting a pressure transmitter.

A) Operating conditions - What will be the operating conditions of the transmitter? How to choose the transmitter case and wetted materials to extend its service life? How to select on the basis of the medium being measured? Are the parts exposed to the medium compatible with or can withstand its particular characteristics? How to ensure that the appropriate type of enclosure/seal is selected? How can we choose between a gauge and an absolute pressure transmitter?

B) Performance Requirements - Is the pressure range being measured in the vacuum or positive scale of measurement? Is every point of measurement stand-alone or are the differences between the two points being measured? How can we determine the minimum and maximum process temperatures?

What Are The Different Types Of Pressure Transmitters?

The pressure transmitters are divided into three types- absolute, gauge, and differential transmitters that are essentially used in measuring various types of process pressures.


Why Use A Level Transmitter?

The level transmitters are mainly used to measure the level of liquid or solid material within a vessel or space. These are the only such type of transmitters that can measure level continuously or at determined points. They provide continuous level measurement and can be used to determine the level of a given liquid or bulk-solid at any given time.

How To Select/Choose A Level Transmitter?

The process of selecting the optimal level transmitter for industrial and commercial processes is affected by many variables. Normally, the selection criteria include physical considerations, including:

  • Phase (liquid, solid or slurry)
  • Temperature
  • Pressure or vacuum
  • Chemistry
  • Dielectric constant of medium
  • Density (specific gravity) of the medium
  • Agitation (action)
  • Acoustical or electrical noise
  • Vibration or mechanical shock
  • Tank size and shape

 While a few of the application constraints are:

  • Price, accuracy and response rate
  • Ease of calibration or programming
  • Physical size and mounting of the instrument
  • Control or monitoring of discrete (point) or continuous levels.

What Are The Different Types Of Level Transmitter?

The seven types of level transmitters used in industries are - point level, continuous level, ultrasonic level, conductive level, pneumatic level, capacitance level, and hydrostatic based.