Review

Although the bulk of the new instruments reaching the market today are benchtop or rack-mount units, demand for portable testers remains sufficiently strong to encourage manufacturers to continue developing new products for this sector of the test and measurement industry. But, with exception of digital multimeters (DMMs) and handheld computers, the majority of new portable testers have specialized uses, such as for performing safety tests, or involve use of PC Cards or similar cards containing test parameters that can be plugged into a portable computer. Here are a selection of portable and handheld instruments introduced over the past 12 months.

Boasting of a new ergonomic design and an easy-access battery door, the XR-Series of digital multimeters (DMMs) from Wavetek Meterman Test Tools (metermantesttools.com) is designed to meet the needs of electronics test, field service and industrial applications. The DMMs range from the basic 30XR unit having a built-in non-contact voltage detector and a "data hold" feature to the top-of-the-line 38XR that can measure 750V true-rms, AC + DC with a RS-232 PC connection. Basic accuracy is 0.25%.

Suitable for gathering and displaying data and designed for one-hand operation, the JETT.ce from Two Technologies (2T.com) is a rugged, 18 oz., handheld computer that supports Windows CE.NET and packs a 200- or 400-MHz Xscale processor, a battery-backed real-time clock, and sunlight readable display with optional touch-screen. The instrument comes with 64 MB of SDRAM and 16 MB of Compact Flash and can be equipped with a compact flash slot.

Powered by a 9V battery or an optional ac wall adapter, the Model 881 handheld tester from B&K Precision (bkprecision.com) can be used to measure the equivalent series resistance (ESR) of electrolytic capacitors in or out of circuit. The portable meter can also be used to make low-value, non-inductive resistor (DCR) measurements. The tester can detect a shorted capacitor in its DCR cycle and also determine its ESR value to indicate if the cap is good or bad. The meter has a measurement range of 0.1 hertz to 30 hertz for capacitors having values ranging fom 0.47 to 2,200 µF. It will not turn-on any solid-state devices in the circuit under test, and it automatically calibrates its internal circuit.

Tensile strength pull testing of coaxial connectors is the specialty of the MPT-100, a portable meter providing up to 200 lb. of force to perform ratchet-action destructive pull-type force tests. Marketed by Midtel Technologies (midtelusa. com), the meter displays the fail force point on an LCD with 0.56" high digits. And it can operate from an ac adapter or a built-in 12V rechargeable battery. The MPT-100 is designed to confirm connector compliance with TL 9000 and other pull-force standards. It measures 2" x 9.5" x 6.25", weighs 2.5 lb., and accepts both 734 and 735 coax cable.

Computer Access Technology (catc.com) has developed an analyzer in a PC Card format that can detect, capture, decode, analyze and display USB data running at speeds of 1.5, 12 and 480 Mb/s. The USBMobile HS card supports the on-the-go (OTG) spec and mass-storage codes—support of OTG allows users to detect, decode and display the HNP and SRP protocols plus data-line pulsing. The USBMobile HS also employs trace software for processing chores.

Designed to precisely scale, digitize and display the output of standard 50 and/or 100 mVdc shunts, the DCA5-20PC ammeters from DATEL (datel.com) span 11 current ranges from 0 to 1A to 0 to 2,000A with ±0.1% guaranteed accuracy. The ammeters connect directly to the shunts and, with exception to the user-supplied shunts, are totally self-contained. The meters include buffered inputs, scaling circuitry, precision reference circuits, 3 1/2-digit a/d converters, LED displays, display drivers, dc/dc converters, and even screw-style terminal blocks for connecting signal and supply lines.

—Joe DelGatto

Outlook

The Future Lies In The Cards
Over the next year, the market for new test-and-measurement instruments is expected to stay on its present course. General-purpose testers such as DMMs and low-end scopes will gain in versatility and performance. Newer special-purpose instruments for performing, among other things, insulation, safety qualification and EMI/RFI testing will debut. And PC Cards and other similar cards loaded with test software that can plug into a portable computer's PCMCIA slot will help grow the on-the-go (OTG) test market.

—JDG