Showing posts with label level control. Show all posts
Showing posts with label level control. Show all posts

Thursday, May 31, 2018

Why Choose Displacer Level Transmitters Over Differential Pressure Level Transmitters?

DP level transmitter diagram
DP level transmitter diagram.
Many technologies have been available over the years have helped the process control industry with level measurement. From basic mechanical float-operated level switches, the process automation industry has been developing new technologies to make industry safer and more efficient.

An example of a "tried and true" technology that was commonly used in the process automation industry is the DP (differential pressure) level transmitter. First introduced in the 1950s, DP transmitters measures the hydrostatic (head) pressure of a liquid in a tank or vessel and interprets this as level, based on the density/specific gravity of the liquid and programmed in by the user. A newer, alternative technology to DP transmitters is the displacer level transmitter, a device also based on specific gravity. While they both are dependent on specific gravity, they are significantly different in areas of installation, accuracy, and maintenance requirement.

Application/Calibration Considerations
Displacer transmitter
Displacer transmitter
  • Infers Level vs. Direct Contact - DP transmitters use inferential measurement to determine level measurement from the hydrostatic pressure.  Despite requiring the specific gravity variable having to be programmed into the transmitter electronics, the level displacer transmitter is in contact with the process media and the level measurement is direct.
  • Time Required to Set up / Calibrate: DP transmitters requires time consuming and expensive calibration/re-calibration if any of the set-up parameters change or if the same DP transmitter is used on different materials in the same tank. Displacer transmitters only require two variables to be programmed (temperature and specific gravity), making it easier when running multiple products in the same tank. Furthermore, many displacer transmitters do not require liquid to be present for calibration. They are programmed (wet or dry) using software. A huge time and money saving over DP transmitters.
Mounting Considerations
  • Orientation and Tank Penetration - The physical mounting of DP transmitters is limited, which can in some situations can become downright problematic. DP transmitters require (2) side-mounted entry locations on the vessel or tank, with one having to be near the bottom. As a general rule, the fewer the entry points of a tank or vessel, the better (because of leakage). Tank bottom entries are all the more so concerning. Displacer transmitters are mounted to meet the requirements of the application and do not require a connection at the bottom of the tank.

Displacer transmitter
Displacer transmitter.
Installation Cost
  • Consider Overall Installed Cost - While DP transmitters have a lower unit cost, adding ancillary components such as tubing and heat tracing can quickly "level" the installation cost playing field. Furthermore, don't discount the time cost savings when setting up, calibrating and re-calibrating displacer transmitters.

Temperature Range Considerations
  • DP transmitters have a normal operating temperature of up to 250°F, with an upper limit of 650°F when special options are specified.
  • Displacer transmitter can be used up to 850°F, very helpful particularly with level measurement in a hot oil separator application.

There are many options and variants to accommodate industrial level applications. Share your level application challenges with instrumentation specialists, leveraging your own knowledge and experience with their product application expertise to develop the most effective solution.

Friday, May 27, 2016

Positive Returns From Steam Generation and Condensate Recovery Efficiency Gain

Two gas fired boilers in a boiler room
Steam systems are excellent candidates for cost saving
through increased efficiency.
The generation of steam is a lifeblood operation to many commercial and industrial operations around the world. The large scale of its use can make steam generation one of the largest energy consumption activities for an industrial plant or commercial building. The size and complexity of steam systems, with generation, condensate handling, heat recovery, and feedwater treatment, provides a number of areas where inefficiencies can cost very substantial sums of money. Conversely, enhancing efficiency toward a maximum attainable level will yield very large savings in operating costs.

Magnetrol International, a globally recognized leader in the design and production of flow and level controls for commercial and industrial use, has produced a video summarizing the elements of the steam system that are good candidates for upgrade, as well as general direction on how to achieve increased efficiency for each. In keeping with the company's line of level and flow measurement products, the focus is on how accurate and robust instrumentation can improve overall system performance and generate a decidedly positive return on the time and funds invested.

Invest a few minutes in the video below and learn how the operating efficiency of your steam system can be elevated with an instrument upgrade. There is a white paper on the same subject available on request. You can also receive a listing of the specific Magnetrol instruments that can be applied to steam systems, with a short description of where each is applied. Reach out to a product application specialist and share your steam system challenges. Combining your system knowledge with their product application expertise will yield the best solution.

Wednesday, May 18, 2016

Radar Level Transmitter Crosses Competitive Price Level

pulse burst radar non-contact level measurement transmitter Magnetrol
Magnetrol Model R82 Radar Level Transmitter
With its ability to reliably detect tank liquid surface level under conditions that prove challenging to other methods, radar technology generally provides an operational advantage over other non-contact level measurement options. Historically, the cost of radar level transmitters for industrial process control applications has hindered their success as a unit of choice for some installations. Magnetrol has changed that imbalance with their recent introduction of a lower cost radar level transmitter for tough applications.

The Model R82 provides radar performance at a price point comparable to competitive ultrasonic units, but maintains the performance advantage inherent in a radar based device. The unit utilizes pulse burst radar technology at 26 GHz, employing advanced signal processing to filter out false echos produced by a range of in-tank conditions that can produce false readings from ultrasonic units.

The short video below provides a closer look at the R82 and its performance advantages. Technical data sheets and any application assistance you may need is available from product specialists. Share your level measurement and control challenges with them and work toward the best solution.

Monday, March 7, 2016

New Product: Non-Contact Radar Level Transmitter

non-contact radar level transmitter for industrial process measurement and control
Model R96
Non-Contact Radar Level Transmitter
Courtesy Magnetrol
A new entry into the non-contact radar level measurement transmitter arena has been released by Magnetrol, a well known manufacturer of level and flow measurement instrumentation for the industrial process control field. The new Model R96 Non-Contact Radar Level Transmitter is intended primarily for applications where continuous fluid level measurement is required.

The company sums up the technical capabilities with their description of the product...

"Virtually unaffected by the presence of vapors or air movement within a vessel’s free space, the two-wire, loop-powered, 6 GHz Radar transmitter measures a wide variety of liquid media in process conditions ranging from calm product surfaces and water-based media to turbulent surfaces and aggressive hydrocarbon media."

The Model R96 level transmitter offers features that combine to deliver a state-of-art instrument for accurate continuous level measurement. A product brochure is included below. Contact application specialists to formulate the right product configuration for your level measurement challenge, or to get more detailed information.

Sunday, March 15, 2015

Float Operated Level Switch Fundementals

Float Level Switch
Float Level Switch
(courtesy of Magnetrol)

Float operated level switches are suitable for use on clean liquid applications alarm, pump control and safety shutdown applications.

These float type units are typically designed, fabricated and certified to compliance with ASME B31.3 specifications.

The design of float operated level switches is based upon the principle that a magnetic field will penetrate non-magnetic materials such as 316 stainless steel. In the case of a float type level switch, the float moves a magnetic attraction sleeve within a non-magnetic enclosing tube which in turn trips an electrical switch mechanism. The enclosing tube of housing provides a pressure seal for the chamber as well as the process.

As the liquid level rises in the chamber (refer to Figure 1), the float moves the magnetic attraction sleeve up within the enclosing tube, and into the field of the switch mechanism magnet. Resultingly, the magnet is drawn in tightly to the enclosing tube causing the switch to trip, “making” or “breaking” the electrical circuit.

As the liquid level falls, the float drops and moves the attraction sleeve out of the magnetic field, releasing the switch at a predetermined “low level” (refer to Figure 2). The tension spring ensures the return of the switch in a snap action.

Wednesday, February 18, 2015

Magnetrol Hygienic Level Control Solutions

Here is a short video that illustrates the use of several level control technologies - guided radar level, ultrasonic level and thermal dispersion -  in hygienic applications.

The video shows us the benefits of each technology and where the Eclipse, Echotel and Thermatel controls are typically used.

For more information on level control in Western PA and West Virginia, contact MS Jacobs at 800-348-0089 or

Friday, October 17, 2014

Magnetrol ECHOTEL Ultrasonic Level Switch Operating Principle

The Magnetrol ECHOTEL utilizes ultrasonic energy to detect the presence or absence of liquid in a single or dual point transducer. Ultrasonic contact level technology uses high-frequency sound waves that are easily transmitted across a transducer gap in the presence of a liquid media, but are attenuated when the gap is dry. The ECHOTEL switches use an ultrasonic frequency of 2 MHz to perform this liquid level measurement in a wide variety of process media and application conditions.

The transducer uses a pair of piezoelectric crystals that are encapsulated in epoxy at the tip of the transducer. The crystals are made of a ceramic material that vibrates at a given frequency when subjected to an applied voltage. The transmit crystal converts the applied voltage from the electronics into an ultrasonic signal. When liquid is present in the gap, the receive crystal senses the ultrasonic signal from the transmit crystal and converts it back to an electrical signal. This signal is sent to the electronics to indicate the presence of liquid in the transducer gap. When there is no liquid present, the ultrasonic signal is attenuated and is not detected by the receive crystal.

For more information on industrial level control, contact M.S. Jacobs and Associates.

Tuesday, October 7, 2014

Introduction to Level Measurement

In many industrial processes, the measurement of level is critical. Depending on the nature of the material being measured, this can be a simple or complex task. Several different technologies for sensing level are briefly explained here.
Gauge or Sightglass
Gauge or Sightglass

Level Gauges or Sightglasses

The simplest form of level measurement for direct measurement of level (almost always visually)  in a vessel. A level gauge (sightglass) is usually a clear tube connected to the a vessel at the highest and lowest part of the level range. The fluid level inside the vessel will be at the same hight as the level in the tube.