Sensor Tips» Chemical Sensor

Smoke Detector IC Boasts Programmability

Randy Frank — Mon, 09 Jan 2012 11:58:37 +0000

Ionization smoke detectors have been around for more than 25 years. Microchip Technology’s RE46C180 ionization smoke-detector IC shows that there is always room for improvement. In addition to being the first with horn synchronization and auto alarm locate, the IC has programmable calibration and programmable feature selection.

Programmable calibration reduces component counts and simplifies setting up smoke detectors during manufacturing. The programmable features allow one IC to be used for multiple smoke-detector models, including models with different battery types, horn patterns and other features. With these integrated features, companies can develop and manufacture a broad range of residential and commercial smoke detectors using a single IC and printed circuit board.

For more information about Microchip’s RE46C180 ionization smoke-detector IC, click here.

Paper and Carbon Nanotubes Combined to Detect Explosive Devices

Randy Frank — Wed, 30 Nov 2011 11:25:15 +0000

Targeting the detection of explosives, such as improvised explosive devices (IEDs), researchers at Georgia Tech Research Institute (GTRI) have developed a prototype sensor that uses carbon nanotubes (CNTs) for the sensing element. The wireless component, a resonant lightweight antenna, is printed on paper or paper-like material using standard inkjet technology. Researchers think the low-cost sensors could be deployed in large numbers to alert authorities to the presence of IEDs and other explosives.

The newest CNT sensor possesses significantly improved sensitivity to minute ammonia concentrations that should enable the first practical applications to detect trace amounts of hazardous gases in challenging operational environments using inkjet-printed devices.

For more information about GTRI’s prototype wireless sensor, click here.

Dissolved Oxygen (DO) Sensors for Continuous Submerged Water Applications

Randy Frank — Mon, 21 Nov 2011 18:02:54 +0000

Wastewater treatment processes that use aerobic bacteria to break down organic compounds in sewage and aquaculture operations require measuring dissolved oxygen (DO) to maintain effect ecosystems. For these and other applications that need to measure DO, Sensorex developed its DO6400 and DO6441 Process Dissolved Oxygen Sensors.

Both sensors use galvanic cell technology and a large volume electrolyte reservoir for long term continuous deployments and have a replaceable membrane. The membrane is available in either Teflon for durability or wide-span HDPE membrane for faster response.

The Model DO6441T Sensor offers a factory-calibrated 4-20 mA output for direct PLC interface. For applications with an external transmitter and a local display, the DO6400 Series is compatible with the Sensorex DO500 and DOMA 4-20 ma loop powered transmitters. The transmitter display can be programmed to read percent saturation, mg/mL or ppm DO.

For more information about Sensorex DO6400 and DO6441 Process Dissolved Oxygen Sensors, click here.

Measure Relative Humidity and Temperature Without Wires

Randy Frank — Tue, 31 May 2011 11:28:56 +0000

Wireless is the must-have attribute for many of today’s consumer and industrial products. When you get two for one, so much the better. With Omega’s UWRH-2 wireless relative humidity transmitter users get both relative humidity and temperature measurements. The battery-powered unit transmits these readings as well as signal strength and battery status back to a host receiver up to 120 m (400’) away.

The unit’s temperature range is -17 to 49°C (2 to 120°F) with an accuracy of ±1°C (±1.8°F). The relative humidity range is 2 to 98% RH with accuracy from ±2.5 to ±3.5 % max depending on the temperature range

For more information about Omega’s UWRH-2 wireless relative humidity transmitter, click here.

Vent Technology Helps Oxygen Sensor Eliminate False Alarms

Randy Frank — Wed, 25 May 2011 12:11:55 +0000

False alarms and premature device failures are issues for some sensors but if the application is detecting safe oxygen levels, the situation is even worse. To address those problems, City Technology developed the 4OXV, an oxygen sensor that incorporates unique vented technology.

Mechanically and electrically compatible with previous generations of City Technology’s 4OX family, the 4OXV’s vented technology and other design improvements reduce lead exhaustion, electrolyte leakage and inappropriate response to environmental variability. These are the three main causes of premature failure of oxygen sensors.

The sensors target industries where reduced or elevated atmospheric oxygen is a potential hazard, such as oil and gas, confined space entry or chemical manufacturing. In these applications, people must be warned instantly if the oxygen level changes.

For more information about City Technology’s 4OXV oxygen sensor click, here.

Infrared Detector Arrays Boast Enhanced Measurement Stability

Randy Frank — Mon, 25 Apr 2011 20:00:50 +0000

For those applications that need to sense PbS and PbSe, Cal Sensors’ LMA (Linear Multiplexed Array) family of lead salt infrared detectors can provide up to 25% increased measurement stability. Consisting of six compensation elements and 250 active elements, the 256-element array provides real-time measurement compensation for environmental changes. Measurement corrections are made based on a comparison of the six compensation elements and three active elements on each side of the array. In addition, the sensors have a much as 10% system noise reduction that provides increased measurement resolution and built-in shielding to isolate the array from measurement variables that could reduce accuracy.

Get more information about Cal Sensors LMA family: PbS and PbSe.

Monitoring the Quality and Blending Accuracy of Fuels

Randy Frank — Wed, 23 Feb 2011 12:28:44 +0000

If you can measure fuel density what else can you do? One thing is make a fuel density meter. That’s exactly what Integrated Sensing Systems, Inc. (ISSYS) has done. Using its microelectromechanical system (MEMS) technology, ISSYS FuelSense meter can measure the different densities of ethanol, biodiesel and gasoline and monitor their purity and mixing ratio.

With UL, cUL and ATEX certification for flammable liquid and gas applications, airports will be among the first places to start using these meters to monitor jet fuel. The technology can also be used for hydrogen and methane applications for density and concentration of binary gas mixtures.

For more information on ISSYS FuelSense Density Meter, click here.

Smoke-Detector IC with Programmable Calibration and Operating Modes

Randy Frank — Fri, 28 Jan 2011 12:41:36 +0000

Integration is the signature of semiconductor technology. Microchip Technology’s RE46C190 3V photoelectric smoke-detector IC integrates a horn driver and boost regulator. In addition, the IC has programmable calibration and operating modes that can be selected and calibrated during manufacturing. This simplifies smoke-detector design and manufacturing. The integrated photoelectric smoke detector requires minimal external components. The 3V sensor operates from two AA batteries.

For more information about Microchip Technology’s RE46C190 smoke-detector IC, click here.

Revolutionizing the Design of Sensor Systems

Randy Frank — Mon, 24 Jan 2011 21:13:56 +0000

Filter Protects Small Digital Humidity Sensor

Randy Frank — Mon, 11 Oct 2010 15:23:42 +0000

It takes a variety of components to make a sensor appropriate for targeted applications and environments. To protect Sensirion’sSHT2x humidity and temperature sensor from water, dust, dirt and various contaminants, the SF2 filter cap is such a component. Made of PBT (Polybutylene Terephthalate) the filter cap has an integrated filter membrane. With a filtration efficiency of 99.99% of all particles >0.1μm, the filter cap is designed to keep response time low. The SF2 fits exactly to the external dimensions of the SHT21 and also serves as an adaptor for mounting the humidity sensor directly into the wall of housing. The use of an o-ring seal results in a waterproof mounting solution that allows protection according to IP67 to be achieved.

For more information on Sensirion’s SF2 filter cap, click, here.