Spring Loaded DC-Operated
LVDT Position Sensors

Macro Sensors’ GHSD and GHSDR 750 Series of 3/4 inch (19 mm) diameter DC-operated LVDTs are designed for a wide range of position measurement applications. These are rugged hermetically sealed sensors, constructed entirely of stainless steel, and intended for general industrial use. The coil windings are sealed against hostile environments to IEC standard IP-68 and electrical termination is through a sealed axial (GHSD) or radial (GHSDR) connector. The radial connector offers two important benefits. First, it results in a through-bore design, which allows for air purging of the sensor's bearings to remove potential contaminants. The second advantage is shorter installed length compared to units of the same range with axial connectors. The mating connector plug is supplied with the unit.

The sensor consists of a spring loaded shaft running in a precision sleeve bearing and connected to the core of an LVDT. The use of a precision sleeve bearing results in measurement repeatability of 0.000025 inches (0.6 μm) or better. The probe shaft is fully extended by a spring exerting a nominal force of 6 to 20 ounces depending upon total range. The contact tip supplied is an AGD standard number 9 made from black oxide hardened tool steel. It is fully interchangeable with other AGD contact tips.

Macro Sensors also offers an air-extend/spring-retract version of the radial model. The GHSDR 750-A is designed for a wide range of cycled position measurement and automated dimensional gaging applications where it is necessary or desirable to move the probe out of the way between readings. The shaft is extended by introduction of a low-pressure (10-30 psi), clean, dry air supply, with a regulated flow, through a 1/4 inch barbed fitting on the end of the unit. With the release of pressure, an internal spring returns the probe to its normal position.

Built-in electronics result in position sensors that operate from a DC input and generate a precalibrated DC output. The output is designed to operate in conjunction with many PLCs, digital indicators, A/D converters, computer-based data processors, and QC data collection systems.

Available in ranges of ±0.020 inch (±0.51 mm) to ±2.00 inches (±50.0 mm), maximum linearity error for a GHSD or GHSDR Series sensor is ±0.25% of full range output using a statistically best-fit straight line derived by the least squares method.

For simplified mounting the GHSD and GHSDR Series have a 1/2-20 UNF-2A thread on the front of the housing, permitting the user to install the LVDT in a mating threaded part or by using the two hex nuts furnished with the sensor. This results in a ready-to-use package for position measurements and longer range gaging applications.