Processing your variables

Trends in process variable transmitters

4-20 mA communication

Use of integrated units goes down

More transmitters offer HART

It’s all about protection. Protecting your equipment, protecting your end product, protecting your job. For process engineers, a good process variable transmitter can be the difference between meeting production objectives and meeting potential disaster.

Control Engineering ‘s 2000 Process Variable Transmitter Study examines the market of these vital components to process engineers. The objectives of this study are to:

Qualify respondents’involvement in recommending, specifying, and/or purchasing process variable transmitters (PVTs);

Examine the types of PVTs respondents currently use;

Determine which manufacturers the respondents have purchased PVTs from in the past 12 months and the number of units purchased; and

Investigate respondent’s estimate of their PVT purchases over the next 12 months.

Control Engineering polled 1,500 of its readers. Three hundred seventeen responded to our questionnaire, resulting in a 21% response rate.

Ninety-five percent of respondents (302) say they specify, recommend, and/or buy PVTs, qualifying their relevant response to this survey.

The largest percentage of respondents performs a combination of batch and continuous processing. According to the survey, 43% say their jobs require them to do both. Following closely in the results are those who perform continuous processing only, with 41% of responses. Batch-only applications accounted for 16% of responses.

The majority of respondents, 57%, say their company’s end product is raw materials, down 10% from last year’s study. Other fabricated metal and miscellaneous manufacturers came in second with 11.6%, while manufacturers of machinery and equipment for manufacturing and service industries was third with 9.3%. Other industries represented are automotive, utilities, and instrumentation and control manufacturers.

More mixing and matching

In a surprising result, many respondents have changed their minds about integrated sensor/transmitter units vs. buying sensor and transmitter from different vendors. They now seem to reserve judgement depending on the application, where last year, 85% respondents said they preferred to buy the complete package, sensor and transmitter, all in one. This year, only 40% of respondents say they prefer to buy a sensor/transmitter in one package. Twelve percent say they want to buy each separately, while nearly half, 48%, say the application determines what they use.

Don Gussin of Milltronics (Arlington, Tex.) says that users’ dedication to certain manufacturers may influence purchasing practices. ‘People have favorite vendors for specific technologies. We have a loyal following for those who need level instrumentation. If people bought specifically from one vendor, we would never have been able to establish our position.’

As to what type of transmitters respondents use, eight of ten use at least one of the big four: temperature, pressure, level, and flow.

Pressure transmitters came out on top, with 95% of responses. Not far behind are temperature transmitters with 93%, while level and flow came in with 84% and 82% respectively.

Multvariable transmitters still have not captured a large share of the market . On average, respondents say that 18% of their total number of transmitters are multivariable. Perhaps the reason for MVTs’ relatively low presence in the market is that most offer digital communications. The Foxboro Company (Foxboro, Mass.) recognized the need to address the large analog installed base. The company’s new I/A Series IMV30 Multivariable Transmitter communicates digitally as well as via 4-20 mA signal. For a breakdown of the results, see graph on previous page.

Analog not going anywhere

To nobody’s shock, analog communication is still the overwhelming preference with respondents. The standard-supported 4-20 mA signal is used by 96% of respondents. Next on the list is HART protocol with 29%, followed by Ethernet with 16% (see graph on previous page).

In the next 12 months, look for 4-20 mA signal to retain its superiority. According to respondents, 62% of them plan to add the analog signal to upcoming control projects. Ethernet will be used by 30% in the next year, while 19% say they will add HART communications to upcoming control projects.

Milltronics’ Mr. Gussin says that more and more users are clamoring for bus connections for their PVTs. He says expect to find more transmitters equipped with DeviceNet, Profibus DP, and Modbus connections. ‘Users don’t realize that to use one of these buses means more process and maintenance information is available to them. That means they can react more quickly to process and instrumentation problems.’

Purchases of process variable transmitters look to be good over the next 12 months. Over half of respondents, 54%, say their company’s purchases of PVTs will at least remain the same. Twenty-three percent say their purchase will increase, while 7% say purchases will decrease over the next year. Sixteen percent say they are not certain.

Process Variable Transmitters

For more information on process variable transmitters, go to www.globalelove.com/freeinfo .

Smart RF level transmitter

霍舍姆。——Drexelbrook普遍Lite射频检测l transmitter is a two-wire RG level transmitter that does not need a hand-held terminal or PC-based software for calibration and configuration. A simple menu-driven display with three integral pushbutton controls walks users through a four-step procedure that sets up an accurate, and linear 4-20 mA output. The display can be set for user-specified engineering units or percent. If HART communication is preferred, users can use a HART Model 275 communicator or Drexelbrook’s PC software for additional features like tank strapping and bench calibration. Universal Lite is designed to accurately measure level independently of process variables, like density, that often interfere with successful level measurement, using other technologies such as bubblers, differential pressure, and displacers.

Drexelbrook

Explosion-proof radar level transmitter

Arlington, Tex.- Milltronics’ IQ Radar 160 is reported to be the industry’s first high-performance, low-cost radar level measurement solution for extreme, hazardous conditions. The company has capitalized on its experience with ultrasonic level measurement, adapting its Sonic Intelligence echo-analysis software for use with pulse microwaves. Using patented microwave design innovations, Milltronics developed pulse-based radar powerful enough to generate a strong return signal, even in tanks where paddles, agitation, and foam can absorb microwave signals. The IQ Radar 160 incorporates a dielectric resonator to avoid frequency instability commonly associated with other pulse radar products. Milltronics echo-analysis software ensures that readings are reliable by filtering out extraneous signal returns commonly found in process and reactor vessels.

Milltronics

Coriolis transmitter is fieldbus certified

Boulder, Colo.- The Model 5300 transmitter is the first Coriolis device to receive official registration from Fieldbus Foundation. The transmitter provides mass flow indication with an accuracy oflosure, and is UL, CSA, and CENELEC approved.

Micro Motion

MVT measures absolute and differential pressure

福克斯波罗,质量。——我/ IMV30多变量一系列交易nsmitter uses polysilicon microsensor technology to measure differential and absolute pressure with a single chip. The patented use of multiple measuring elements on a common silicon substrate simplifies construction of the transmitter to increase reliability. In addition to multiple pressure measurements, the new transmitter also measures and transmits process temperature (using a separate temperature sensor) and provides sophisticated flow rate calculations. The I/A Series IMV30 multivariable transmitter features on-board computing power to calculate flow rates of liquid, gas, or steam using familiar, low-cost head-class flow elements. All real-time process measurements are communicated to the system in digital format. In applications where measurements are communicated via analog signals, any of the real-time process measurements or calculated values may be assigned to the 4-20 mA output.

Foxboro

Transmitter with online help

Sepulveda, Calif.- Moore Industries’ TDZ Smart HART Temperature Transmitter supplies accuracy rates of up tos, using a standard HART handheld Model 275 communicator, or Moore’s Intelligent Configuration Software with the comprehensive online HelpMap system. The transmitter can handle direct RTD/thermocouple types, millivolt; and resistance/potentiometer inputs. It provides a completely isolated 4-20 mA output with HART digital information superimposed, that is ready for direct interface with indicators, recorders, DCS, PLC, and PC-based SCADA systems. The HelpMap system is modeled after an interactive web site, and functions as a searchable users’ manual designed to provide quick answers to common problems.

Moore Industries

Transmitter adds HART

Phoenix, Ariz.- Honeywell IAC has added a HART protocol to its ST 3000 Release 300 Smart Pressure Transmitters. Other options available with the HART protocol include a configurable digital display and local zero and span adjustability. The transmitter is fully compliant with the HART Communication Foundation Specifications and communicates with any compliant HART host device. ST 3000 is also available with 4-20 mA output, FOUNDATION Fieldbus output, and Honeywell’s Digital Enhanced protocol to fit any customers communications needs.

Honeywell IAC

MVT is Fieldbus ready

Chanhassen, Minn.- Model 3244MV comes with a FOUNDATION fieldbus connection. This multivariable temperature transmitter’s capabilities include standard function block programming; an 18-bit analog-to-digital converter with ambient temperature compensation; and transmitter-sensor matching, which eliminates RTD sensor interchangeability error for optimal system accuracy. New features include the Regulatory Control Suite, which offers two PIDs, one signal characterizer, and one arithmetic function. The unit also offers a LCD meter, giving the user visual indication of temperature measurement, status, and diagnostics.

Fisher-Rosemount

Transmitter offers customization

Greenwood, Ind.- Cerabar M, from Endress+Hauser, allows users to select the transmitter’s housing, technology, and electronics options that best meet their application requirements. Cerabar M’s modular design enables it to be used in all industrial environments, providing gage and absolute pressure of gases, vapors, and liquids. Communications options for Cerabar M include 4-20 mA or HART. Smart technology provides simple set up, maintenance, and operation. In addition to a conventional metallic diaphragm, Endress+Hauser offers a high-performance ceramic sensor. With stainless steel housing, the ceramic sensor excels in sanitary applications in the food, beverage, and pharmaceutical industries.

Endress+Hauser

Customizable two-wire transmitter

Rochester, N.Y.- 500T/T5 Series Electronic Pressure Transmitter is a two-wire device with 24 V dc output signal linear to the input pressure. The unit provides what is reportedly a highly reliable, field-proven sensing system, available with a wide variety of seal types, fill fluids, and capillary lengths to create a broad line of remote seal systems available. The 500T/T5’s hermetically sealed hybrid electronics have only 16 components and a 80-year MTBF. 500T/T5 Series offers noninteractive zero and span, and comes with a seven-year warranty.

ABB

Transmitter certified by TÜV

Spring House, Pa.- Moore Process Automation Solutions’ XTC Critical Transmitter is said to be the only transmitter certified by Germany’s TÜV organization, which rates equipment for requirement class levels to specify the amount of safety risk reduction required by a particular application. Features include hardware and software redundancy, a comprehensive self-testing system, and primary and secondary current sources to ensure safe shutdown if a failure occurs. Because the transmitter is a member of the XTC family of transmitters, it integrates with the company’s APACS+ pro-cess automation system and the companion QUADLOG safety PLC, enhancing the systems’ ability to deliver a comprehensive plant solution by improving total safety and availability for critical processes.

Moore Process Automation Solutions

RH temperature transmitter

Flanders, N.J.- The 650 temperature transmitter is a rugged transmitter available in a variety of mounting options depending upon application requirements. These mounting options include regular wall-mount, duct-mount, and remote-mount installations. Features include

Testo

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