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FAQ Position Sensors and Electronics H. G. Schaevitz LLC Learn more about our linear position sensors and electronics. Need to talk to an engineer? Call us at 856-727-0250
ASG LVDT Signal Conditioning modules Graphic User Interface (GUI) Instructions1. Connect a 2-wire RS-485 port converter to the computer on which this GUI is to run and connect the converter's output terminals to the RS-485 bus connections on the LVDT module(s), Data A (D-) connects to terminal J3-2 and Data B (D+) connects to terminal J3-1, but always follow the data polarity (D) indicated above, regardless of the letters used for the data lines. Linear Position Sensor Calibration using SenSet® Field ProgrammabilityAlliance Sensors' LVIT Linear Position Sensors offer SenSet® Field Programmability. SenSet® allows the installer to very simply and quickly exactly match the full scale electrical output of a sensor to the actual mechanical movement range of the device in which the sensor is installed. GE Position Sensors on Power Gen TurbinesHow they work and how to use them with a third-party LVDT signal conditioner designed specifically for Power Gen Applications LVDTs (Linear Variable Differential Transformers) are very commonly used as position sensors in power plants throughout the world. Working from AC voltages and frequencies not available from power lines, LVDTs require a signal conditioner to provide the necessary operating power. Alliance Sensors Group's model S2A module, designed specifically to be used in power gen applications, is considered by many power gen users be the most advanced and easy to use single channel LVDT signal conditioner on the market today. It can operate practically any inductive or LVDT-type position sensor currently in use. Quick Start Guide Installation of MR-7 Series In-cylinder Position SensorsMechanical installation: MR-7 in-cylinder position sensors are designed to be inserted into an o-ring port machined into the rear endcap of the hydraulic cylinder. Standard MR-7s use an SAE J1926-1 -8 port with a 3/4-16 UNF thread. Metric threaded versions use an ISO 1649-1 port with a M18 x 1.5 thread. Both ports are Illustrated below. For either size port, the sensor's male thread comes with a Viton o-ring installed. SAE J1926-1 -8 Port Quick Start Guide ME-7 In-cylinder Position Sensor Installation
Mechanical installation: An ASG ME-7 in-cylinder position sensors is embedded into a 48 mm diameter
cavity in the rear endcap of a hydraulic cylinder. It may be inserted from the front of an unassembled
cylinder or from the rear of a cylinder with a two-piece endcap with a separate end cover.
What's So Good About LVIT Technology and What Is It All About, Anyway?Alliance Sensors Group, a division of H.G. Schaevitz, LLC, has developed a linear position sensing technology called LVIT that offers an excellent price-to-performance ratio compared to other linear position sensing technologies such as LVDTs, linear potentiometers, and magnetostrictive devices. Furthermore, LVITs can offer the best stroke-to-length ratio of any contactless linear position sensor, because their overall length only increases by a relatively small percentage beyond their stroke. Grounding practice to minimize ground loop issues for sensors with a common I/O groundConcerns about the effects of a common ground on the individual outputs from multiple ASG’s LVIT sensors can be remedied by using a single ground point. This ground point, which should be made at the input ground of electronics used to monitor or measure the sensors’ outputs, is where the power ground/output ground lead for each of the sensors is connected, along with the power supply’s ground. Separate connections are used for each sensor’s power positive and output. By connecting sensors in this manner, variations in the ground currents or output currents of individual sensors are not combined into the outputs of any other sensors in the system. This grounding connection approach obviates the need for isolated outputs and is the universally recommended grounding practice for minimizing ground loop issues. However, if a customer is unable to make the recommended grounding connection, multi-channel isolation modules are available from several sources at relatively low cost per channel. Connecting to Alliance Sensors Group’s current loop output LVIT sensorsAlliance Sensors Group, a div of H G Schaevitz LLC, Moorestown, NJ, USA, makes position sensors utilizing Linear Variable Inductance Transducer (LVIT) technology which offer analog outputs of both voltage and current loop, the most common of which are 0 – 10 Volts DC and 4 – 20 mA DC. A voltage output is typically used in applications that have a receiving device, i.e.: PLC, DAQ system, or readout, located close by so the interconnecting wiring is not very long and can be shielded if necessary to prevent noise or EMI being coupled into the output. 4 to 20 mA Current Loops Made EasyUnderstanding current loop output sensorsFor analog sensor data transmission, a 4-20 mA current loop is a very common method to convey the sensor data acquired. Sensors or transducers are usually designed to measure a range of values of the measured parameter, which is known as the measurand. The measurand value must be converted to current within the measuring device in such a way that the current in the loop will be proportional to the measurand value. The range of the loop current, 4 mA to 20 mA, is called the span of the transmitter. The transmitter is typically configured so that one end point of the measurement value will correspond to 4 mA and the other end point value measured will correspond to 20 mA. The 4-20 mA current loop has become the standard for signal transmission and electronic control in most analog control systems. A 4-20mA current loop circuit is shown in Figure 1. In a current loop, the current is drawn from a DC loop power supply, then flows through the transmitter using field wiring connected to a loop load resistor in the receiver or controller, and then back to the loop supply, with all elements being connected in a series circuit. All current-loop-based measuring systems use at least these four elements. Our Technical Support Staff: We have more than 150 years and three generations in the position sensor business and are expert application engineers at what we sell. We have real world experience and know how to solve your measurement challenges. Need technical help with your measurement application? Call us today 856-727-0250. Our Web Site: We are constantly improving our website and adding new sensors to our product offerings.
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