Everything You Always Wanted To Know About LVDTs But Were Afraid To Ask

1. Everything You Always Wanted To Know About LVDTs But Were Afraid To Ask - - - or - - - �What The Hell Is An LVDT, Anyway?�

2. L V D Ts What is an LVDT? An LVDT is a Linear Position Sensor With a Proportional Analog Output An LVDT has 2 Elements, a Moving Core and a Stationary Coil Assembly

3. L V D Ts What Do the Letters LVDT Stand For?

4. L V D Ts Linear Variable Differential Transformer Transformer: AC Input / AC Output Differential: Natural Null Point in Middle Variable: Movable Core, Fixed Coil Linear: Measures Linear Position

5. FYI: Macro Sensors LVDTs Macro Sensors LVDTs have range specified as � from null position Nominal range is part of Model No. Total range is 2x nominal range

6. Macro Sensors LVDT Model Numbering Initial Letters : LVDT Series Designation Numbers Following Letters: Diameter or Body Size in Thousandths of an Inch Following Dash: Nominal Range from Null in Thousandths of an Inch Standard Option: Dash, then 3 Digits Special Unit: Dash Followed by 4 Digits

7. Macro Sensors LVDT Model Numbering Example: PR 750-1000- 010 LVDT PR = PR Series General Purpose LVDT 750 = 0.75 inch (3/4 Inch) Diameter -1000 = Nominal Range of �1.00 Inch; Total Range of 2.00 Inches - 010 = Optional Teflon Bore Liner

8. L V D Ts

36. How to Select an LVDT First Choice to Make: Free Core vs. Guided Core Free Core Frictionless Operation Possible Mechanically Coupled Core Guided Core Bearings with Friction, Stiction, etc. Spring- or Air-Loaded Core

37. Free Core LVDTs Generally Less Expensive Many Ranges and Sizes to Choose More Complicated to Install

38. Guided Core LVDTs Usually Simpler to Install Perceived as More Expensive More Limited Selection of Ranges and Limited to Short Strokes

39. How to Select an LVDT Second Choice to Make: AC in / AC out vs. DC in / DC out AC operation: External Support Electronics DC operation: Built-in Support Electronics

40. AC in / AC out ADVANTAGES Flexible in Applications- Span and Zero Adjustable, etc. Many Ranges and Sizes to Choose More Robust to Environments LIMITATIONS Requires External Support Electronics Requires Extra Connections to LVDT Potential Electrical Noise Susceptibility Potential Problems with Long Cables

41. DC in / DC out ADVANTAGES Simpler to Hook Up Precalibrated Operation Several Input/Output Choices LIMITATIONS Temperature Environment No Span or Zero Adjustability Size Constrained by Internal Electronics

42. Free Core AC LVDT Series PR General Purpose, Many Ranges PRH G. P. Legacy Replacement CD Miniature Size, Shorter Ranges HSA Hermetically Sealed, Blind Bore HSAR Hermetically Sealed, Thru Bore SQ Heavy Duty Industrial Housing HLR UL Listed Class I, Div. 2 HazLoc HSE Hermetically Sealed, Blind Bore HSER Hermetically Sealed, Thru Bore

43. Free Core DC LVDT Series DC General Purpose, Voltage Out HSD Hermetically Sealed, Blind Bore HSDR Hermetically Sealed, Thru Bore HSDI 4-20 mA Loop Powered (2-Wire) PRDC Legacy 24 Volt, Ratiometric I/O PTI 4-20 mA Loop Powered (2-Wire) FM Approved Intrinsically Safe (I.S.) Class I, Div. 2 Hazloc with Barriers

44. Free Core DC LVDT Series HSE Hermetically Sealed, Blind Bore* HSER Hermetically Sealed, Thru Bore* HSDI 4-20 mA Loop Powered (2-Wire) PRDC Legacy 24 Volt, Ratiometric I/O PTI 4-20 mA Loop Powered (2-Wire) FM Approved Intrinsically Safe (I.S.) Class I, Div. 2 Hazloc with Barriers * Available fall 2005

45. Guided Core LVDTs Sleeve Bushing or Linear Ball Bearing Spring Extended (push LVDTs) Spring Retracted (tension LVDTs) Air Extended, Spring Retracted

46. Guided Core LVDT Series GSA Lowest Cost, AC only GHS Good Precision, AC and DC GHSR Good Precision, AC and DC BBP/T Highest Precision, AC only GHSR-A Air-Extended GHSR Series GHX Air-Extend, Long Retraction BBP/T-A Air-Extended BB Series

47. LVDT Support Electronics *** For AC LVDTs only *** DCM-1000 DC Powered OEM Electronics* LPC-2100 AC Line Powered* LVC-2412 24 Volt DC Powered* DMC-A2-Series Dual Channel Controller DMI-A1 Series Single Channel Controller * Discontinued as of mid 2006

48. LVDT Support Electronics DCM-1000 Unpackaged PC Board for OEMs Roughly Same Cost as DC LVDT Voltage Output Only, w/ Span + Zero +/- 15 V DC Input Power

49. LVDT Support Electronics LPC-2100 DIN-rail Mounting Voltage or 3-Wire Current Output AC Power Line Operation Span and Zero Adjustments

50. LVDT Support Electronics LVC-2412 DIN-rail Mounting Voltage or 3-Wire Current Output 12 - 24 V DC Operation Span and Zero Adjustments

51. LVDT Support Electronics DMI Series Single Channel Indicator AC Power Line or 24 VDC Operation 5-1/2 Digit LED Display Adjustable Set Points 2 or 4 5-Amp Relay Option RS 232 / Ethernet Output Options Software Scaleable Analog Outputs

52. LVDT Support Electronics DMC Series Dual Channel Controller AC Power Line or 24 VDC Operation 6-1/2 Digit LED Display Scrolling setup screens Adjustable Set Points 4 5-Amp Relays RS 232 (Std) / (Ethernet Optional) Software Scaleable Analog Outputs

53. Macro Sensors Over 400 Years of Collective Experience In The LVDT Business

54. FACILITIES 20,000 Sq. Ft. Facility in Pennsauken, NJ ISO 9001 Certified Company Certificated November 8th 2000.

56. CERTIFICATIONS Underwriters Laboratories - HLR Series AC-LVDTs Factory Mutual Factory Mutual Intrinsic Safety Certification for PTI 750 Series Loop-Powered Position Transmitters CE DC 750 Series DC LVDTs DCSE Series DC LVDTs HSD, HSDR Hermetically Sealed LVDTs GHSD, GHSDR Spring Loaded DC-LVDTs