Question 1

What is an LVDT and how does it work?

Accepted Answer

An LVDT (Linear Variable Differential Transformer) is a high-precision, frictionless displacement sensor that converts linear position into an electrical signal. A free-floating ferromagnetic core rod moves inside a coil assembly; as it moves, the differential inductance between two secondary coils changes, producing a voltage proportional to displacement. The contactless operating principle gives LVDTs infinite resolution and unlimited operating life.

Question 2

What LVDT series does AGMPL manufacture?

Accepted Answer

AGMPL manufactures 8 LVDT series under the Positron brand: Standard AC (AS, 22mm body), Slimline AC (AM, 9.5/12.7mm), Ultra Thin AC (AU, 8mm), Waterproof AC (AW), High Temperature AC (ASH, up to 150°C), Standard DC (DS), DC Voltage Output (DSV, 24V supply), and DC Current Output (DSA, 4–20mA). The DPL draw wire transducer extends the range to 10m strokes.

Question 3

What is the difference between AC and DC LVDTs?

Accepted Answer

AC LVDTs output a raw differential AC voltage and require an external signal conditioner to supply the AC excitation and demodulate the output to a usable DC signal. DC LVDTs (DS, DSV, DSA series) have a built-in signal conditioner — simply connect a DC power supply and read the output voltage or current directly, with no external electronics required.

Question 4

What measurement strokes are available?

Accepted Answer

From ±1mm (2mm total stroke on the AM/AU slimline series) up to 10m with the DPL draw wire transducer. The standard AS/DS series covers ±5mm to ±350mm (700mm total stroke) in the same 22mm body. The DSV/DSA series covers ±25mm to 750mm, and the ASH high-temperature series covers ±5mm to ±100mm.

Question 5

How accurate are AGMPL LVDTs?

Accepted Answer

Up to ±0.25% FSR non-linearity on small-range models, with temperature coefficients below 0.025% FSR/°C. Infinite resolution is inherent to the inductive operating principle. All units are individually calibrated and ship with NABL-accredited calibration certificates traceable to national standards.

Question 6

Can AGMPL manufacture custom LVDTs?

Accepted Answer

Yes. Custom stroke lengths, body diameters, special housing materials, hermetic sealing, non-standard connectors, and other modifications are available for both standard and specialist LVDT types. Use the LVDT Questionnaire or contact our engineering team with your requirements.

Question 7

What signal conditioning is required for AC LVDTs?

Accepted Answer

AC LVDTs need an external signal conditioner providing AC excitation (typically 1–5V rms at 1–5 kHz) and demodulating the differential output voltage. AGMPL supplies compatible signal conditioner and digital indicator modules. DC LVDTs (DS/DSV/DSA) have built-in conditioning and need only a DC supply.

Question 8

Which industries use AGMPL displacement sensors?

Accepted Answer

AGMPL LVDTs are widely used in automotive testing, aerospace R&D, railways, defence, material testing laboratories, geotechnical engineering, textile machinery, process automation, civil and structural monitoring, medical equipment manufacturing, and industrial R&D facilities.

Series	Model	Diameter	Range	Linearity	Supply	Output	More
AC LVDT Series
AS	Standard AC LVDT	22 mm	±5 to ±350 mm	0.25–1.0% FSR	±15V AC	AC Voltage	More →
AM	Slimline AC LVDT	9.5 / 12.7 mm	±1 to ±60 mm	0.25–0.4% FSR	±15V AC	AC Voltage	More →
AU	Ultra Thin AC LVDT	8.0 mm	±1 to ±10 mm	0.3–0.4% FSR	1–3V rms, 2 kHz	AC Voltage	More →
ASH	High Temperature AC LVDT	22 mm	±5 to ±100 mm	0.25–0.4% FSR	±15V AC	AC Voltage	More →
AG	Precision Gauging LVDT	16 mm	1–20 mm	0.25% FSR	±15V AC	AC Voltage	—
AE	EcoLine with Micrometer	22 mm	1–200 mm	0.75% FSR	±15V AC	AC Voltage	—
AW	Waterproof AC LVDT	22 mm	±1 to ±25 mm	0.3% FSR	2V rms, 1–5 kHz	AC Voltage	More →
DC LVDT Series
DS	Standard DC LVDT	22 mm	±5 to ±350 mm	0.25–0.8% FSR	±15V DC	±10V / 0–10V DC	More →
DSV	DC LVDT — Voltage Output	32 mm	±25 to ±350 mm	0.25–0.6% FSR	24V DC	±10V / 0–10V DC	More →
DSA	DC LVDT — Current Output (4–20 mA)	32 mm	100–750 mm	0.5–0.8% FSR	24V DC	4–20 mA	More →
Draw Wire / Potentiometric Series
DPL	Draw Wire Displacement Sensor	Aluminum housing	0.5–10 m	<0.3% FSR	5V DC	Potentiometric (5–95% Vex)	More →

Displacement Sensors (LVDT)

Overview

Product Series

Standard AC LVDT

Technical Specifications

Draw Wire Displacement Sensors

Draw Wire / String Pot Transducer

Signal Conditioners & Power Supply

Signal Conditioner Modules

Arduino LVDT Shield

Zeus5000 Indicator & Logger

DC Power Supply

Accessories & Calibration

Extension Rods

Tips & End Attachments

Calibration Bench

Pocket Calibrator

Clip-On Extensometers (DEXEM Series)

Need a Custom Sensor Solution?

Frequently Asked Questions

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