Handheld Test and Measurement Instruments

Demand for advanced capabilities continues as devices get smaller, faster, cheaper.

Form follows function. The phrase originated with American sculptor Horatio Greenough and was popularized by architect Louis Henri Sullivan, but its wisdom also applies to product design. As the need for portable test and measurement equipment grew, manufacturers of these devices initially learned that the box was the optimal shape for containing and protecting the inner workings. Whether beautifully finished wood, cast or formed metal, black phenolic resin, with or without handles or wheels, form indeed followed function.

Microelectronics, component miniaturization, and advanced materials/molding techniques, however, have put old equipment in new forms: smaller, lighter, rugged, faster, and more accurate. In this case, form no longer had to follow function.

In an online survey, conducted by Control Engineering and Reed Corporate Research, industrial users involved in specifying, recommending, and/or buying handheld test and measurement equipment indicated their technical requirements and preferences and purchasing habits. Their responses showed similarities to, and some surprising differences from, the previous survey conducted in 2002.

Who measures what

Of those specifying, recommending, and buying handheld test equipment, 82% said they used them for in-plant requirements, 5% used them for OEM (resale) market applications, and 13% purchased them for in-plant and OEM requirements. Applications varied. Thirty-six percent used testing devices in continuous and batch processing applications, 24% for utility services, 15% for discrete products manufacturing, 10% for continuous processing, 9% for batch processing, and 6% for other applications (see accompanying pie charts).

Regardless of application, measurement use trends show some change over the past 4 years. Electrical parameters are still measured most, with 36% saying they use these devices for this purpose. Calibration accounted for 14%, and electrical power measurements for 14%. (In the previous survey, electric power measurements were part of a broader electrical parameters category. It included position/ dimension values, force/torque measurements, and acceleration, accounting, at least in part, for the high 61% score in 2002.) This year, the “big four” process variables maintained their 2002 rankings with temperature at 8%, flow at 3%, pressure at 3%, and level at 1%. The remaining discrete manufacturing variables and event frequency were interspersed among them. The accompanying chart shows the detailed breakdown.

Use of electrical power measurement devices shown in this survey reflects today’s soaring energy costs. Although a majority of electricity is generated by coal, still a relatively cheap commodity, pollution regulations have increased power plant operating costs. Portable electric power measurement helps engineers evaluate the impact of energy-efficient retrofits and conversation efforts.

Single use versus multifunctional

Multifunctional handheld test and measurement tools offer real productivity advantages. A meter that can take several measurements makes it easier for a technician to cover the plant floor quickly. But this year’s survey shows some changes in use of multifunctional tools over the previous one. In the variable measurement area, the popularity of multivariable devices dropped, although they are still favored over a single function meter. In the area of calibration meters, however, use patterns were reasonably steady, with multifunctional devices remaining more popular than single function devices although their earlier lead decreased slightly. Multifunctional analytical meters experienced the greatest change. Dominance of multipurpose devices in this area evaporated over the last four years, putting use of single and multipurpose meters in this survey at virtually the same level.

A number of factors may have contributed to the relatively sudden popularity decline of multivariable devices. According to Jonathan Rowe, product manager, transmitters for Invensys Process Systems, Measurements & Instruments Div., choosing the type of instrument to use is being complicated by the growing number of options available. Although a trend toward singlepurpose test tools seems to be emerging, he observes, many users still prefer multipurpose devices because they minimize the number of instruments they have to purchase, store, and maintain.

He adds that users “are finding that recent advances in the technology and sophistication of handheld devices for specific applications provide performance benefits that outweigh the negative aspect of having to maintain more devices. Some of the recent developments pushing the growing use of single-purpose test devices are miniaturization, whereby more computing power is available for handhelds, and the growing number of digital field instruments with which users can interact using handheld configurators and calibrators.”

Ranking performance factors

In this survey, users rated the following factors as “very important” in their search for the optimum handheld test and measurement device:

• Accuracy/repeatability;
• Durability;
• Ease of use;
• Easy to read;
• Cost;
• Warranty; and
• Availability/quick delivery.

There is a limit to what companies will pay for handhelds, however. Bill Southard P.E., president of DST Controls, says, “Although most users of handheld test equipment say they want the best, the most accurate, lightest, and easiest to use device regardless of cost, things can change once the purchase request gets to the boss and the purchasing department. The boss wants the simplest handheld available for the job. The user wants repeatability and accuracy. Purchasing wants to get three bids and to compare functions.”

When all is said and done, ease-of-use and cost top the decisionmaking list, adds Southard. “We live in an integrated world. My list would read ease-of-data entry, ease of integration with database, cost, availability, and warranty. Accuracy/ repeatability is usually enough and basic durability—with the exception of explosion-proof models—is expected.”

Form may follow function, but not if the present handheld test and measurement vendors have their way. The trend today appears to be to supply the controls community with many forms to do whatever function suits the measurement needed, be it single or multifunctional.

Handheld test, measurement products

Portable configurator blends flexibility, functionality

Foxboro HHT50 configurator for use with any HART or FoxComcompatible field device integrates a Microsoft Windows XP operating system, Field Device Tool (FDT)-based software, and its developer’s standard PC50 configuration software in a PC Tablet chassis, providing flexibility and functionality in a portable device. Also available is a PC50 version 2.0, which supports USB connections along with new HART scan functionality and Foxboro CFT50 Coriolis flowmeter configuration capability. XP Pro Tablet PC operating system expands functionality beyond a specific-use PDA or similar handheld device.

www.foxboro.com/instrumentation

Invensys Process Systems, Foxboro Measurements & Instruments

Thermal imager for troubleshooting

Ti20 thermal imager is designed for infrared troubleshooting and predictive maintenance applications. It includes a portable noncontact radiometric camera that measures temperature from 14 to 662 ºF. Cost is less than US$6,500. It measures absolute temperature and captures 14 bits of information on all of its 12,288 pixels, displaying the thermal image and temperature reading on a large color LCD. Users can adjust critical parameters, including emissivity, reflected temperature compensation (RTC) values, palette, level, and span, and high and low temperature alarms, in the camera or using the bundled software.

www.fluke.com.sg

Fluke Corp.

Portable data station

Datum-Y network-enabled portable multi-channel datalogger is reported to be the first to be certified for IPv6 (Internet Protocol version 6). It measures and records, in the field or plant, environmental data including temperature, voltage, current, power, vibration, speed, and rpm, and can use various communication media for alarms, remote data collection, or to change settings. It is housed in a compact, rugged case with detachable terminal block to wire easily up to 8 or 16 channels of thermocouple, RTD, or dc voltage inputs, including two digital inputs and one pulse input. Model XL100-1 (8 channel) and XL100-2 (16 channel) portable data stations are equipped with a 3.5-in. color LCD monitor with wide angle viewing.

www.yokogawa.com.sg

Yokogawa Engineering Asia