Sensor Business Digest
SENSOR INDUSTRY DEVELOPMENTS AND TRENDS

December 2001

Synergistic Acquisitions Enable Sensor Companies to Broaden Their Market Reach
In the highly competitive sensor industry, well-conceived and executed strategic acquisitions can allow a sensor company to expand its product offerings, more quickly amass significant market share, and gain a greater presence in new promising or expanding markets. SBD underscores, however, that mergers and acquisitions should be undertaken carefully in order to ensure that the partnering companies truly have highly complementary products and served markets. An acquisition will likely have particularly effective results in cases where the collaborating companies have already established a foothold in certain markets/applications, which can be expanded and deepened by the resources available through the acquisition.

Gems Sensors' (Plainville, CT, 860-747-3000/800-378-1600) acquisition of Setra Systems (Boxborough, MA, 978-263-1400/800-257-3872), finalized in December, illustrates key ingredients for a successful acquisition, resulting in a union of two companies with very complimentary products and synergistic served markets. Moreover, the sensing technologies and application expertise of Gems (which manufactures liquid level, pressure, and flow sensors and controls) and Setra (a manufacturer of capacitive pressure transducers, as well as pressure transmitters and accelerometers) can be leveraged to create significant, new market opportunities.

"Setra will be a great addition to the Gems family given its solid positioning and strong reputation with customers in key served markets," stated Steve Breitzka, president of Gems Sensors, Inc. "Setra's capacitive technology product platform and low pressure focus make it a natural complement to Gems' transducer product line. This acquisition greatly enhances our collective ability to meet both the needs of target market markets as well as the general OEM and end-user markets we presently serve."

Breitzka told SBD that Gems and Setra have highly complementary products and serve complementary markets. By combining their product offerings and sales channels across product lines, they can expand their reach in existing markets/applications and cultivate new market opportunities. For example, Setra's expertise in low pressure sensors can be used to expand Gems' opportunities in varied markets/applications, including remote tank inventory monitoring. There are, moreover, opportunities in the future for combining Gems' and Setra's sensing technologies to enhance their offerings and extend their served applications in various market segments, including HVAC.

Breitzka noted that Gems Sensors focuses on solving problems for OEM designers, and has a strong capabilities in providing customized sensor solutions for specific applications. Gems strategy, reflected in the acquisition of Setra, is to further add to their comprehensive platform of products and technologies to address key customer needs with respect to sensing fluids in machines and equipment.

Gems Sensors' diverse array of fluid level, flow, and pressure sensor products primarily serve OEMs. Major markets for Gems' sensors include HVAC/R (heating, ventilating, air conditioning and refrigeration), semiconductor processing, medical, environmental , and oil and gas exploration.

Gems' liquid level sensor products include solid-state conductance level sensors; continuous and point ultrasonic level sensors; electro-optic level sensors (which use an infrared LED and a light receiver); and magnetic float-type visual level indicators. Their flow sensor products include electronic, Hall effect flow sensors, and reed switch flow sensors. Gems provides CVD (chemical vapor deposition) and sputtered thin-film pressure transducers, as well as pressure switches that use a piston/diaphragm design (which purportedly incorporates the high proof pressure of piston technology with the sensitivity of diaphragm designs).

Gems' CVD pressure transducers, flow sensors (e.g., Hall effect and reed-type), and level sensors (e.g., magnetic visual level indicators, electro-optic level switches, float type/reed switch level transmitters, level switches) are used in semiconductor processing applications. Applications for in the semiconductor processing arena for Gems' flow, level, or pressure sensors include CVD/PVD deposition equipment; dry/wet water etch equipment; ion implant systems; diffusion furnaces; wafer preparation equipment/CMP; recirculators; chemical delivery systems; cleaning equipment; vacuum pumps; gas scrubbers; and in-plant (e.g., monitoring sulfuric acid in day tanks, deionized water tank level indication, safety shower alarm trigger, monitoring high-purity solvents). Breitzka noted that Gems' pressure transducers compete successfully against silicon micromachined pressure sensors in high-vibration environments, such as earth-moving equipment. Their highly stable CVD sensors, which are typically priced above $50, are made using plasma enhanced chemical vapor deposition (CVD) technology. In the CVD process, a plasma gas stream guides chemical vapors that form silicon dioxide (glass) molecules onto stainless steel wafers. The process is repeated to deposit a polysilicon strain gauge layer on top of the glass layer. The thin film is atomically fused directly to the steel surface of the gauge beam, thereby following the shape of the beam very accurately. The atomic fusion is the foundation for the CVD sensor's performance and stability. The CVD strain gauge is affixed to the sensor assembly via a precise, automated laser weld process.

Applications for Gems' CVD pressure transducers include off-highway vehicles (load weighing systems, load moment indicating); natural gas equipment (compressors and dispensing equipment); semiconductor processing (wafer manufacturing); power plants (piping steam pressure); refrigeration (compressors and lube oil pressure equipment); robotics/factory automation equipment; and HVAC (compressors).

Gems' 1200 series OEM CVD transducers (which have an ASIC coupled with a thicker diaphragm that allows the sensor to withstand most pressure spikes) can provide a long-term drift of only 0.2% full scale per year and a typical full scale accuracy of 0.5%. The 1200 series CVD pressure sensors have been used to enhance the effectiveness of high-pressure misting systems that enable turbine generators to provide peak output throughout the year. High water pressure is required in the system to assure that the water droplet size is sufficiently small to ensure vaporization before entering the turbine.

Gas-fired turbine generators of 1 to 12,000 kW in size are popular for providing supplemental power to businesses and industry. However, such turbine generators produce less power on hot days when more power is typically required. To surmount this problem, the air is cooled before it enters the turbine, typically through water evaporation. Two major methods for providing evaporative liquid are a water-soaked medium over which air passes, or high-pressure water misters that spray atomized water droplets into the air intake. Water misting systems can provide greater control over the air cooling process, compared to simpler water-soaked static media.

The 1200 series CVD pressure sensor has solved the high-pressure sensing requirements for manufacturers of turbine generators and developers of water-misting evaporator systems. Such systems are subject to water hammer and can have pressures in excess of 2300 psi. The 1200 series has a proof pressure that is four times over the maximum measured pressure.

The sputtering process is similar to the CVD process in that, at the molecular level, different materials are fused together to produce a very stable composite. Sputtering is performed in a vacuum and uses inert gas molecules to dislodge target material molecules that are sent at very high speeds, colliding into another substrate (the diaphragm). The kinetic energy imbeds the target material into the diaphragm. Gems notes that the method allows a metal diaphragm to be sputtered with almost any material. Gems sputters stainless steel diaphragms with glass, metallic strain gauges, titanium for inter-bridge wiring, and gold for bond pads. Sputtered metallic strain gauge sensors are described as offering excellent thermal properties and superior stability specifications.

Gems' sputtered thin-film pressure transducers (which are typically priced at over $200) can provide very high accuracy and stability in demanding environments. For example, the 3000 series, designed for mission-critical applications, use advanced thin-film technology that eliminates the need for using delicate bonding wires, which can disintegrate under conditions of high shock and vibration. Such sensors also offer a warm-up time of less than 100 milliseconds and RFI (radio frequency interference) immunity.

Gems' Silver Bullet T conductance liquid level sensors are solid-state devices that detect the presence/absence of an electrically conductive liquid. Such sensors are purportedly immune to probe erosion, due to their alternating potential electronics. In the conventional conductivity probe, the metal from the probe will be removed (via electrolysis) when a single potential (DC voltage) is applied to the probe. In contrast, the Silver Bullet liquid level sensor uses an alternating potential configuration (AC voltage or frequently reversing DC voltage), preventing degradation. When an alternating potential is applied, the metal removed in the first half-cycle is replaced in the second half-cycle, virtually eliminating any loss of probe material.

Applications for the Silver Bullet sensors include coolant level monitoring in radiators and expansion reservoirs; waste water level monitoring; leak detection; water level monitoring in a separator; ultrasonic cleaning equipment; and steam boilers. Gems' Silver Bullet conductance liquid level sensor has been able to successfully address the level sensing requirements of, for example, an off highway vehicle customer who changed its coolant formulation, which rendered the previous (capacitive) sensor that they had been using ineffective. The new coolant created a coating problem on the sensor probes, rendering the sensor's response unacceptable. Gems succeeded in developing Silver Bullet sensor, which was selected as the replacement sensor for the coolant level sensing application.

A custom ultra-compact FS-3 piston-type Reed flow switch from Gems has helped enhance the reliability, performance, and affordability of medical dialysis machines, which perform two functions when biological kidneys fail: purify the blood of deadly toxins; and treat over-hydration by removing excess fluids consumed by a patients in between dialysis treatments.

Over 800,000 patients worldwide suffer from chronic renal failure, resulting in accumulation of toxic substances in the blood and over-hydration. The hemodialysis process used external equipment that allows the patient's blood to be pumped through a dialysis machine equipped with a hemodialysis membrane-the artificial kidney.

A key manufacturer of high-tech dialysis machines asked Gems to improve the sensing capability of their latest dialysis machine to speed patient treatment. A thermal dispersion flow sensor incorporated in the company's dialysis machine product line contributed to high maintenance costs from repeated servicing. The thermal flow sensor was incapable of responding fast enough to the very high temperatures that occurred during sterilization cycles. The sensor's slow reaction time to flow (or lack of flow) across the two points of its temperature probes resulted in undesired alarms. The ambiguous flow condition, ultimately, led to equipment shutdown.

After evaluating ultrasonic, magnetic, and other thermal flow sensing technologies, the dialysis equipment manufacturer selected Gems' custom FS-3 flow switch design. The sensor chosen met the application's performance specifications and requirements, including a very low set point, molding the sensor in a preferred material specified by the customer, meeting the extremely high temperatures required for the sterilization cycle, longevity (e.g., millions of operations), and circuitry to match the output of the thermal dispersion flow sensor being replaced.

Gems' standard FS-3 flow switch is designed for pure water applications, such as controlling reverse osmosis systems, point-of-use equipment, and water-dispensing equipment. The FS-3 is equipped with a magnetic piston that is displaced by the pressure differential from liquid flow to magnetically actuate a hermetically-sealed reed switch isolated within the unit's body. A stainless steel return spring de-actuates the switch when flow decreases. Pressure drop is low, since the FS-3 has an in-line configuration with a straight-through flow path. The custom versions provide the dialysis machine manufacturer with a positive flow/no flow to accurately monitor flow conditions.

Gems' new Messenger T remote monitoring telemetry system, with a 33.6 kpbs modem, is designed to provide vital inventory supply information and to enhance vendor-managed inventory operations by tracking and reporting conditions at multiple remote, unattended, or inaccessible locations. The Messenger XL-70--which is designed to minimize customer inventory, reduce lead time, and prevent costly run-outs--is compatible with a wide range of sensors and communicates in data, voice, and fax modes. The system can record a minimum of 10,000 time/date stamped events and transfer data for scheduling preventive maintenance or analyzing equipment problems. Via MessengerNet T, remote data is displayed in custom-designed screens, hosted on Web reliable servers. The acquisition of Setra can help expand opportunities for the Messenger XL-70, since Setra's low pressure transducers could be used along with the Messenger XL-70 to monitor the inventory level of smaller tanks.

Founded in 1967 by Dr. Y.T. Li and Dr. S.Y. Lee, professors emeritus of engineering at MIT and co-developers of the variable capacitance transduction principle, Setra Systems suppliers pressure transducers and transmitters for such applications/industries as industrial, OEM, barometric, HVAC/R, environmental, test and measurement, food and pharmaceutical, agricultural, medical, and semiconductor. Setra is focused on meeting the unique requirements of such industries, and they develop pressure transducers/transmitters that address new and challenging custom applications. Major applications for Setra's pressure transducers include test and measurement and building HVAC systems (i.e., measuring differential air flow across the air filter in the ductwork, which allows for determining whether the air filter is clogged and needs to be replaced).

Setra's capacitive pressure transducers are designed to provide high accuracy and long-term stability. In a typical configuration, a compact housing contains two closely-spaced, parallel, electrically-isolated metallic surfaces, one of which serves as a diaphragm capable of slight flexing under applied pressure. The diaphragm is constructed of a materials with low hysteresis, such as 17-4 PH SS or a proprietary compound of fused glass and ceramic (Setraceram T). The secured surfaces (or plates) are mounted so that a slight mechanical flexing of the assembly, caused by a minute change in applied pressure, alters the gap between them, thereby creating a variable capacitor. The resulting change in capacitance is detected and converted by Setra's proprietary ASIC (application specific integrated circuit) to a proportional high-level analog signal. The custom integrated circuit uses a patented charge balance principle.

An example of Setra's commitment to provide a customized solution for a customer's particular requirements is illustrated in Setra's collaboration with Unit Instruments (Yorba Linda, CA) to provide a pressure transducer for monitoring the status of Unit's compact, clean Z-Bloc modular gas delivery system for the semiconductor industry. Setra's custom solution played a key role in the development of the Z-Bloc. Unit Instruments, Inc. manufactures gas flow controllers, ultra-high purity gas isolation boxes, and ultra-clean gas panels for the semiconductor industry.

Setra has noted that retooling for the next generation of wafer processing equipment makes cleanliness in wafer processing increasingly vital. Such retooling will also boost the efficiency of IC chip production by facilitating the processing of more 300 mm (12") diameter wafers than 200 mm (8") wafers in each process load. A semiconductor process tool, a self-contained, automobile-sized unit, handles the operations for fabricating patterns on wafers, from loading the pure wafers to outputting a patterned wafer.

Owing to the costly premium on workspace for such process tools, wafer fabrication laboratories want process tool makers to minimize any increase in their tool size, while accommodating their redesign for larger loads of 300 mm wafers. The fabrication support industry is, therefore, seeking approaches for reducing the volume of their subsystems and components, where possible, while simultaneously increasing their reliability to minimize downtime.

The gas delivery system, one of the subsystems of the semiconductor process tool, is vital for IC pattern development and must deliver clean and controlled gases reliably. A reduction in the size of the gas delivery system helps offset the necessary expansion of other process tool components to accommodate 300 mm wafer production, such as wafer transport and the process chamber.

In response to retooling requirements for compactness, cleanliness, and ease of maintenance, manufacturers have created gas delivery systems that utilize gas sticks built in the form of channeled stainless steel blocks. The gas flow control components need only be attached to the channeled block on one side to complete the gas flow channels that are drilled into the blocks.

Unit's Z-Bloc modular gas system, based on a top-mounted gas stick design, addresses volume reduction issues, and uses seals and components that render it very compact, clean, and accurate. Setra started working with Unit during the early R&D phase of the Z-Bloc, and they were quite willing to adapt their product to fit Unit's needs.

Setra modified their model 215 capacitive pressure transducer for use in Unit's Z-Bloc by welding the transducer to a flange, so it would easily mount to the Z-Bloc. Setra's model 215, which has a 316 stainless steel diaphragm and a an insulated electrode plate, offers stability and accuracy of one-quarter percent full scale, which helps reduce maintenance downtime for recalibration. Moreover, the model 215 helped enhance the stability, accuracy, cleanliness, and compactness of the Z-Bloc.

The pressure transducer's output signal is fed to the process tool computer, which monitors the status of all the gas sticks. The computer can shut down wafer processing when the pressure status throughout the gas delivery system suggests a malfunction has occurred. In the event of a malfunction, the repair technician can analyze the pressure status and identify the location of the component failure. The technician can also view local pressure readings on a swivel-base display mounted to the model 215.

The Z-Bloc uses 316L VIN+M/VAR stainless steel for its block, and its internal channels are passivated by a chromium oxide layer to minimize specialty gas corrosion. Components on a single stick are top-mounted and consecutively positioned along its extended steel block. The "in" and "out" ports of each component are positioned to the block's internal V-shaped channel configuration. This design allows internal connections of each neighboring component to complete the flow path through the gas stick and eliminates the need for space for tubing and fittings. Therefore, the size of the gas panel decreases up to 75%. Moreover, the configuration allows direct access to each component, and uses standardized component mounts which allow flexibility in positioning components on the stick.

Z-Bloc's reliability is enhanced by the Z seal joints developed by Unit. These joints are sealed simply by tightening four socket-head cap screws without any complicated tightening sequence or torquing. In the sealing process, the component mount and the block incorporate machined glands, which compress a malleable nickel seal to purportedly produce a leak-free system. Under installation, the seal does not produce any particles greater than 0.1 microns, and produces less than 10 particles greater than 0.02 microns. The particles are typically purged out the system in less than one minute.

In addition, Setra now offers an integral static pressure probe for duct mounting that is available with its model 267 series of low differential pressure transducers. The probe, constructed of extruded aluminum and measuring 7.8" in length, is suitable for typical duct sizes. It has a baffle at the tip to minimize any velocity pressure errors; and is designed with a gasket to seal against the duct, which prevents leakage.

The model 267 series allows up to 10 psi over-pressure (in either direction) without damaging the unit. The sensor's thermally matched coefficients promote enhanced temperature performance (thermal error of less than 0.033% full scale/degree F from +40 to +150 degrees F) and long-term stability. The 267 series offers 1.0% accuracy, and optional accuracies of +/- 0.4% and +/- 0.25%. The 267 with an optional LCD display has a +/- 0.5% full scale accuracy. The model 267 can be used with unregulated 24 VAC or 24 VDC power supplies, and is available with 3/16" O.D. barbed brass pressure fittings for push-on tubing. Electrical connection is accomplished through a screw terminal strip with PG-9 or PG-13.5 cable strain relief or conduit termination. The 267 is IP65/NEMA 4 rated, has a UL94V-O flammability rating, and complies with the European requirements of Council Directive 89/336/EEC.

The model 267MR, well-suited for users who need to configure on the fly, offers up to six pressure ranges (bi-directional and uni-directional) in each transducer, reducing inventory from 20 single range units to four. The ranges include +/- 0.1" W.C. (water column) full scale to 30" W.C. full scale. The voltage output is field-configurable to either 0-5 VDC or 0-10 VDC. A 4-20 mA output is also available.

Furthermore, Setra's Weighing Systems division provides counting scales, laboratory balances, and load cells (that use the company's variable capacitance ceramic sensor technology), as well as bar code accessories for weighing and data logging. Setra Weighing Systems is purportedly among the major counting scale suppliers in the U.S. Their counting scales are used to count a wide range of parts, including semiconductor chips, injection molded parts, fasteners, diodes and other electronic components, coins, fish, and seeds. Setra's load cells are used in varied specialty weighing applications, such as manufacturing of radio-pharmaceuticals, color matching for paint and ink manufacturing, and moisture balances for the food processing industry. Setra's load cells are used in paint mixing scales at numerous automobile collision repair shops in North America.

Gems Sensors is part of the Process Environmental Controls segment of Danaher Corporation (Washington, DC)(NYSE: DHR). In FY 2000, Danaher had net sales of nearly $3.8 billion, an operating profit of $552,149,000, and net earnings per share of $2.23. In FY 2000, the Process/Environmental Controls segment accounted for 65% of Danaher's sales and 67% of Danaher's operating profit.

For the nine months ended September 28, 2001, Danaher had sales of $2.86 billion, a 4% increase over the comparable period a year ago. Net earnings for the nine month period ended September '01 were about $264.6 million, or $1.78 per share, representing gains of 12% and 9%, respectively, over the comparable 2000 net earnings and earnings per share.

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