Photodiode meter tests laser
The uses of laser diode modules (LDMs) are exploding in fiber-optic telecom networks, computer peripherals, and medical applications. Keithley Instruments' Model 2500 Dual Photodiode Meter's twin channels are geared for testing LDMs using features such as fast, low-level current measurement, optical power measurement, and extended voltage output capability. The built-in picoammeter can resolve currents down to 10 femtoamps, an order of magnitude better than competing units, according to the company—which supports dark-current measurement of a non-illuminated photodetector. The Model 2500 can measure photo current through an LDM's back detector or optical power from the laser diode using a user-selected optical test head.
Keithley Instruments: Product Code 5136 or
Two recent low-power, 16-bit analog-to-digital converters (ADCs), the TC3400 (one differential input) and TC3402 (four differential analog inputs and multiplexer), from TelCom Semiconductor target portable battery-powered devices such as medical and remote industrial process control equipment. Both feature a two-wire MicroPort™digital interface for serial communications with a system microcontroller. Conversion rates are 8/sec at 16-bit resolution, up to 512/sec at 10-bit resolution. "By eliminating some of the power management interface circuitry, these new devices can be offered with lower quiescent power dissipation in a smaller, reduced-cost package," says Don Ashley, manager of advanced products. The ADCs operate from 1.8 to 5.5V, and draw 250µA operating (0.75µA in the sleep mode). The TC3400 comes in compact 8-pin SOIC and PDIP packages; the TC3402 in 16-pin PDIP and QSOP sizes.
Semiconductor: Product Code 5137 or
The TetraLight is the latest addition to the Tetra family of ruggedized portable computers from Logic Instrument, and is geared for test, measurement, and data acquisition in aerospace, telecommunications, and automotive industry applications. Measuring 11.4×13×1.85 inches, the PC-tablet TetraLight features a high-brightness touch screen and can be outfitted with hard disk drives and the latest processors, such as the Pentium III Series. It also operates with an infrared keyboard and docking station with CD-ROM or DVD-ROM. The tablet PC meets IP51 standards for shock, vibration, and operating environment.
Logic Instrument: Product Code 5138 or
Claimed by Analog Devices to be the world's smallest tilt/motion sensor, the ADXL202E is a two-axis, low-power accelerometer in a 5×5×2-mm package. The MEMS device features vibrating finger beams having 1µfeature size. Full-scale range is±1.5g with a resolution of 0.005g. Supply voltage ranges from +2.7 to +5.25V with less than 0.6 mA current. Applications include vibration and shock measurement, automotive (air bag systems), and hand-held devices and electronic games (vibration and orientation sensing).
Analog Devices: Product Code 5140 or
The Rugged Temperature Probe provides high-accuracy temperature sensing under the harshest conditions, according to Sensor Scientific. "Probes are made to the customer's individual rugged specs," says Bob Gliniecki, sales engineer and director, "and they are used extensively in applications such as aircraft engines and railroad locomotives." The devices come in thermistor and platinum-RTD element versions—with accuracies at OC of 0.05 and 0.03C, respectively. Also key is the integrated stainless-steel sensor well and hermetically sealed connector which resist moisture, vibration, mechanical and thermal shock, and corrosives.
Sensor Scientific: Product Code 5139 or
The InstruNet Series is a high-accuracy distributed data-acquisition system from Omega Engineering for Windows 95/NT and Macintosh computers, which the company says has become a top-selling product. The family's topology uses a controller board plugged into the computer, and external A/D boxes for direct connections to sensors, including thermocouple, voltage, and strain sensors. Each A/D box has 16 single-ended and eight differential 14-bit analog inputs, eight analog outputs, and eight digital I/Os. The controller card in the computer can connect to 16 A/D boxes on a network up to 1,000 ft away. System throughput is 166,000 samples/sec and signal-to-noise is 78 dB.
Omega Engineering: Product Code 5141 or
encoders tout compatibility
Modern machine-tool systems users are demanding reduced downtime following interruptions. Absolute linear and angle encoders from Heidenhain are geared to accomplish this goal, along with having serial-interface compatibility with GE Fanuc and Mitsubishi controls. Absolute systems provide the absolute position reading upon being switched on, thus no need for the time-consuming, reference-point traverse needed with incremental encoders. The Heidenhain encoders use a proprietary absolute-scanning technology, which does not require any battery backup. Safety is also enhanced, the company says, by virtue of reliable position information, relative to operators, which is available at all times.
Heidenhain: Product Code 5142 or