Application-Specific Sensors

Spectrometers, humidistats, and robots are such different products that they require quite distinct sensors with unique specifications. Near-infrared spectroscopy and imaging applications that use linear arrays for imaging sensors require a specific wavelength range. The humidity measurements in weather stations, copiers, and printers, must be cost-effective and have closely controlled accuracy. The sensing requirements of robots and sensitive equipment on moving platforms dictate acceleration and gyroscope measurements in all three axes. A common trend for all of these applications is integrated signal conditioning and/or processing in the sensor for improved performance and ease of use.

HUMIDITY SENSOR

Humidity not only is a key measurement, excessive humidity affects the proper operation of sensitive equipment, such as copiers and printers. Honeywell's HIH-4000 series of humidity sensors provides instrumentation-quality relative humidity (RH) sensing in a cost-effective package to address cost-sensitive applications. The sensor's package has a recessed die mounting for better handling protection. Set in thermoset polymers, a capacitive sensing die interacts with platinum electrodes to provide a linear voltage output versus percent RH. On-board signal conditioning includes laser-trimming (2 percent RH accuracy) that makes units interchangeable. In addition, fast response time allows the sensor's use in instrumentation-grade equipment, while low current draw makes the sensor ideal for battery-operated systems. For more information on Honeywell's HIH-4000 series of humidity sensors, go to http://rbi.ims.ca/4417-528.

WIRELESS GYROSCOPE AND ACCELERATION SENSOR

Measuring and communicating complex motion control data get easier when the sensor provides tri-axial measurements and supports a variety of communication options. The Inertia-Link, a wireless inertia sensor from MicroStrain, has three orthogonal rate gyroscopes, three orthogonal accelerometers, a microprocessor, data logger, and RF transceiver. In addition to the wireless IEEE802.15.4 protocol, the unit also supports USB, RS-232/485, and CAN bus communications. With a package size of only 44 x 58 x 21 mm and weight of 45 gm (without battery), the fully calibrated and fully temperature-compensated (over a range of -20 to +60C) sensor provides digital data output rates and user adjustable sampling rates. For more information on MicroStrain's Inertia-Link, go to http://rbi.ims.ca/4417-526.

FOCAL PLANE ARRAYS

Targeting telecommunications, moisture sensing, and spectrometer applications, as well as industrial inspection, Sensors Unlimited's InGaAs linear photodiode array detects light in the short wave infrared (SWIR) spectral range. The SU1024LE operates in the wavelength range of 0.8 to 1.7 µm and provides up to 107 pixels per second read-out with pixel heights of 25 or 500 µm. The tall pixels are frequently used in optical spectrometers and arrays with 1024 square pixels are more common in high-resolution imaging of industrial processes. Optimized to deliver low noise, high uniformity, and few dropouts with high quantum efficiency, the arrays come as components or installed in a Linescan camera. For more information on Sensors Unlimited's linear arrays, go to http://rbi.ims.ca/4417-527.