Throughout civilization, humanity has devised ways to record events for future generations: word-of-mouth, cave paintings, symbols on clay tablets, alphabets on scrolls. Not long after the industrial revolution, it became apparent to manufacturers that recording data was better accomplished through technology.

By Dick Johnson March 1, 2007

Throughout civilization, humanity has devised ways to record events for future generations: word-of-mouth, cave paintings, symbols on clay tablets, alphabets on scrolls. Not long after the industrial revolution, it became apparent to manufacturers that recording data was better accomplished through technology.

A recent Web-based survey by Control Engineering and Reed Research Group found that recorders/data loggers are still in use in a number of applications. Of some 500 control professionals queried, almost two-thirds were using recorders in-plant or in an OEM application. Primary applications were diverse (see accompanying chart). Batch and continuous processing at 42% accounted for the most use. Continuous processing ranked second with 25%. The next largest segment (14%) was for utility services (including electric power and gas pipeline applications). Discrete product manufacturing applications represented 8% of the total, batch processing 8%, and testing, diagnostic, and troubleshooting applications were smallest at roughly 2%.

Measuring the big four

Recorders are used in a variety of applications. Most common are for batch and continuous processing at 42%. Only 2% of survey respondents use the devices for testing, diagnosis, and troubleshooting.

Process variables of most interest to control engineers include temperature, pressure, flow, level, and various analytical measurements (pH, ORP, etc.). These values help track and control the process, ensure quality control, and provide documentation for the many compliance issues industry faces. According to the survey, temperature, pressure, and flow account for the majority of measurements taken by recorders. They are used overwhelmingly in the continuous and batch processing industries. Measuring electric power use also garnered many responses, coming in close behind measured process variables.

Power use measurement has wide application in process and discrete operations. Relative humidity also accounted for a fair number of responses in this area. An interesting note: hydrogen ion concentration (pH), an analytical variable of interest in water and wastewater operations, got the least number of responses. (See accompanying chart.)

Many types, many variables

When recorders were surveyed in 1999, strip chart recorders surpassed circular chart recorders in popularity. This year’s survey reinforces that trend as strip chart recorders (paper-based and paperless) remain the most popular type specified. Of those using circular chart recorders, 72% used ink on paper, 21% used thermal marking, and 30% opted for paperless technology. Of those using strip chart recorders, 50% used ink on paper, 27% thermal technology, and 68% paperless. Ink remains the most popular paper-based recording medium by a 3-to-1 margin over thermal markers, despite the added cost of consumables and maintenance to keep pens filled and functioning properly.

Any recorder can be a multi-channel device. With the ability to handle 10 or more measurements per device, they bring an end to the one-recorder-per-variable setup common with early recorders. Circular chart recorders have an advantage over strip chart recorders, says Dan Gawel, quality engineer for the Dickson Co. Some customers “do not use strip chart recorders because a circular chart recorder offers full-view of the entire recording, an important feature for many users…. Hundreds of applications share a common need: a critical item and process needs to be monitored,” says Gawel.

Not yet wireless; market factors

Recorders are used to measure process variables, most commonly temperature (88%) and pressure (68%).

Devices with wireless communication are rife in industry today. Although not all applications lend themselves to wireless, control device manufacturers continue to explore that capability. According to survey respondents, 66% do not use wireless technology in recorder applications. The remaining third said they use “some wireless technology,” but use is not widespread. Even among those who say they use wireless capabilities for recorders, most apply it in less than 1% of applications.

Adaptation of wireless technology has been slow and not without problems, said Dan Stack, president of Telatemp Corp. “Wireless is certainly a growth area,” he noted, “but it hasn’t yet penetrated our marketplace. Early adopters are the companies that own their own fleets, have control over these assets, and need to centralize data retention and analysis. Barriers to wireless include the initial costs of converting fleets to this technology. But on-going maintenance, system support, and compatibility issues also exist. Many large organizations have found it difficult to gain value from establishing large data networks for monitoring as opposed to their existing reliance on electronic data loggers or paper strip chart recorders,” said Stack.

Alex Niculescu, senior automation engineer for DST Controls, a systems integrator, agreed. “Wireless recorders have not come into the mainstream. We have successfully implemented a few wireless applications where data had to be gathered from portable equipment. These, however, were done in situations where running cable to the equipment would have made it more difficult to relocate later.”

According to the survey, spending for recorders will increase in the next year. Among respondents, 27% report increased spending, while 55% anticipate no change, and 18% will spend less.

Control professionals expecting to spend more on recorders in the next year have much to ponder. What attributes should they be looking for? DST Control’s Alex Niculescu offers these points to consider:

Availability—Uptime is of concern to most customers, especially on a device that gathers data for record keeping.

Availability—Uptime is of concern to most customers, especially on a device that gathers data for record keeping.

Rugged construction—the less susceptible to physical damage, the less downtime a recorder will see.

Long-term data availability—Electronic storage methods should be at low risk for obsolescence. Paper media (ink and thermal) and electronic storage should be stored so that there is little risk of damage or destruction. This point is often the most important selection criterion.

Easy data exchange—Engineering personnel and management often need plant-floor data as they are gathered. A recorder that allows recorded data to be readily shared with other computers is a time and labor-saving advantage.

Effective data presentation—How well are data presented? Are charts and screens easy to read? Are the decodable identifications of data (pen identification, units of measurements, time stamps) easily read?

Types of inputs allowed—The ability to allow various input signal types and communication buses may be an important selection criterion.

Additional functionality—The ability to alarm, trend group points, plot two values against each other, and calculate trendable values based on recorder inputs are additional important factors to consider.

Price, often a consideration, should be considered after other required attributes.

Recorders, related products

The companies below, identified by Control Engineering subscribers as leading providers of recorders, offer the following products.

Find other suppliers at . To find system integrators with related expertise, go to . Control Engineering Product Research reports are available free at / .

Online: More companies, recorder products

Other companies that survey respondents identified as leading suppliers of recorders follow. (Products are described with this article online, at under March 2007.)

ABB SM500F field-mountable videographic recorder

Siemens Energy & Automation Sirec D200, 300, and 400 video display recorders

Astro-Med Dash 8Xe portable data collection

Dickson TH800 temperature, humidity chart recorders

GE Industrial EPM 7430D power quality meter .

Beyond survey results, others suppliers of recorders include the following. Read more at .

Moore Industries-International Net Concentrator System

Logic Beach IntelliLogger portable system

Teletemp 12-channel scanning thermometer

Zodiac Data Systems D7000 recorder .

DAQ, display stations

DXAdvanced latest generation Daqstation from Yokogawa provides panel-mounted solutions for process measurement, display, and data historian applications. DX1000 offers 2-12 universal inputs, 5.5-in. color display. DX2000 has 4-48 universal inputs and 10.4-in. color display. Using Modbus RTU or TCP communications, an external input option allows the DX2000 to handle 300 additional external I/O inputs. All include 80 MB or optional 200 MB of internal flash memory, and use standard Compact Flash removable media. USB memory drives can retrieve data, and a common USB keyboard can be used for configuration when an optional USB port is specified. Standard Ethernet connectivity functions include Web server, e-mail messaging, FTP file transfer, SNTP synchronization, and Modbus TCP. Yokogawa Corp. of America

Traceability, paperless

Paperless eZtrend QXe recorder from Honeywell is said to fit in a standard DIN-sized panel (144 x 144 mm) for easy replacement of 100 mm strip chart recorders. Features include large internal flash memory (without the need for a battery) expandable up to 400 Mbytes that provides removable secure data storage; ease of use through universal and counting inputs, color TFT display, touchscreen, keyboard and mouse operations, data transfer on USB keys, and multilingual user interface. Connectivity includes two USB ports. Ethernet and RS-485 communication ports allow users to retrieve data and configure the recorder remotely. Recorder complies with 21 CFR Part 11 and can be installed in a U.S. FDA validated process. Honeywell Inc.

Graphic recorder features remote access

Model 6000XIO distributed graphic recorder from Eurotherm Chessell (part of Invensys, along with Foxboro) lets users view and archive data remotely from numerous operator displays. Applications include furnaces, water and wastewater treatment, power generation, and for 21 CFR 11. It allows processes to be viewed with similar or custom displays. It features an intuitive, touchscreen display for viewing process data in varying formats, onboard Flash data storage capability, Ethernet communication, and a CompactFlash card. Recorder can be accessed via LAN, dial-up connection, intranet, or Internet. Eurotherm Chessell

No paper or wires recorder

Model 1620A DewK Thermo-Hygrometer from Hart Scientific (part of Danaher, along with Partlow, Anderson, and Fluke) is a paperless temperature and humidity monitor system for real-time data collection. It has Ethernet, optional wireless capability, and LogWare III, a client-server database program to consolidate and monitor data in one database from any licensed computer in the facility. Dual-sensor, graphical data logger/analyzer offers real-time and historical display and analysis of temperature ( Fluke Corp., Hart Scientific

Universal circular chart recorder

Microprocessor-based, portable Ctxl Supercorder from Omega Engineering comes in computer room white or charcoal gray in ranges of 2-120 °F and 2 to 98% RH. It uses four D-cell batteries or a universal ac adaptor and has an 8-in. chart for 1-, 7-, or 32-day recording. Features include a large, bright, dual, backlit display unit that monitors minimum, maximum, and average values and includes front panel keypad programming. All models have chart rescaling through a PC interface. Chart data are stored in non-volatile memory with a built-in real-time clock to monitor input data vs. time. RS-232 PC interface allows download of recorded data. Omega Engineering Inc.

Author Information

Dick Johnson is a consulting editor with Control Engineering. Contact him at