HSTA And HSTAR Sensors Resist Heat And Vibration

Macro Sensors' HSTA and HSTAR LVDT-based linear-position sensors offer the environmental resistance and short-stroke sensor body length for cylinder applications where these are critical. While linear-position sensors were once considered too long for hydraulic applications, the development of new winding techniques, such as computerised layer winding and improved microprocessing, has considerably reduced the length of the linear-position sensor body compared with its measurable stroke length. In fact, for short-stroke actuators and cylinders (less than 6in), Macro Sensors' linear-position sensors can be much shorter than a magnetostrictive sensor.

These linear-position sensors are hermetically sealed and AC-operated. They measure 3/4in (19mm) diameter and can survive in temperatures up to 200C and withstand high levels of shock and vibration. Coil windings are sealed against hostile environments to IEC standard IP-68. They are offered with either an axial (HSTA) or radial (HSTAR) connector - units can have a through bore for the fluid to pass or can seal the fluid in the RAM. The radial connector makes the installed length of the HSTAR LVDTs at least 2in shorter than comparable units, with an axially mounted connector for easier installation in tight spaces.

Accessible from both ends, the linear-position sensors can be easily cleaned of grit, dirt, dust or other contaminants for greater reliability and longer life. Available in ranges of +/-0.050in (+/-1.25mm) to +/-10.0in (+/-250mm), the HSTA and HSTAR sensors feature the high resolution, excellent repeatability and low hysteresis associated with LVDT (linear variable differential transformer) technology, as well as the highest sensitivity consistent with good linearity. The maximum linearity error for any of these sensors is +/-0.25 per cent of full-range output using a statistically best-fit straight line derived by the least squares method.

Macro Sensors offers custom designs for higher temperatures and pressure resistance, smaller diameters and connector options. HSTA and HSTAR Series LVDTs operate properly with any conventional differential input LVDT signal conditioner. Ranges of 1in or greater will also work with ratiometric LVDT signal conditioning. Macro Sensors offers a full line of LVDT signal conditioners that deliver optimum performance from any HSTA and HSTAR linear-position sensor.

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Kavlico Releases LPG And CNG Pressure Sensors

Kavlico has released a line of liquefied petroleum gas (LPG) and compressed natural gas (CNG) pressure sensors to support vehicles and industrial equipment using alternative fuels. These fuel options are being adopted by municipalities and other governmental agencies as an option for fleet vehicles such as cars, buses, trucks and fork lifts. Typical applications include monitoring and measuring low pressure for fuel rail, high pressure for tank pressure or combined pressure and temperature.

The sensors are utilised to optimise fuel metering and control combustion, improving emissions and engine performance. The original equipment manufacturer (OEM) will design in a Kavlico fuel rail sensor to measure the absolute pressure of the fuel at the inlet of the injectors. Kavlico's stainless-steel LNG and CNG sensors utilise a thin-film (TiON) sense element and are available in pressure ranges up to 250barG.

Operating on 5VDC, the sensors provide a linear amplified analogue output of 0.5-4.5VDC proportional to pressure. The operating temperature range is -40C to +140C across the full operating range. The lightweight sensor can be configured with a variety of electrical and process connections to meet each OEM's application-specific requirement.

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City Technology Enhances Hydride Gas Sensors

City Technology has enhanced and extended its Sensoric range of hydride exotic gas sensors. These sensors all use an ionic liquid electrolyte to provide improved output level stability, responsiveness and overall performance improvements in the aggressive environments in which they operate.

The new arsine and silane sensors are improved versions of existing gel-based devices, and three new sensors, characterised to detect phosphine, diborane and hydrogen selenide, have also been introduced.

According to City Technology, the ionic liquid combination has excellent thermal stability with no measurable vapour pressure, offering results even when subjected to wide variations in operating temperature, relative humidity and gas flow rates.

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Position Sensors For Accurate Down-Hole Drilling

Macro Sensors is offering LVDT-based linear position sensors for position feedback control of down-hole drilling equipment, such as bore scopes that measure the ID of the drilled hole. The LVDT linear position sensors for down-hole applications are custom built to survive high temperatures and high pressure. Units are rated for pressures to 20,000psi, in electrically non-conductive, chemically benign media, at continuous temperatures up to 400F.

The high-temperature ratings are achieved by using special construction materials for the linear position sensors that include special high melting point soldering. To accommodate high pressures, the sensor case is vented to equalise pressure inside and outside of the LVDT linear position sensor.

Offering a compact 3/8in diameter design, these AC-operated LVDT linear position sensors can serve as an integral part of devices with tight space restrictions. A lightweight low mass core also makes the small, contactless linear position sensors suitable for applications with high dynamic response requirements. Units operate with any conventional differential input LVDT signal conditioners to provide position feedback back to operators at the surface.

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