Summary of LVDT Info from email and other inquiries:
Manufacturers:
1. Lucas Schaevitz
N. America:
Lucas Control Systems Products
Schaevitz Sensors
1000 Lucas Way
Hampton, Va. 23666
800-745-8008
Fax: 800-745-8004
Europe:
Lucas Control Systems Products
Schaevitz Sensors
543 Ipswich Road
Slough, Berks SL1 4EG
U.K.
0753-537 622
Fax: 0753-823 563
Types: AC and DC
2. Solartron Metrology (markets or manufactures Schlumberger Industries
LVDT's)
Steyning Way, Southern Cross Industrial Estate
Bognor Regis, West Sussex
PO22 9ST
U.K.
+44 0 1243 825011
Fax: +44 0 1243 861244
Also Locations in France, Germany and USA
U.S.A.: Tel 716 634 4452 Fax: 716 634 1225
France : 33 1 69 53 63 63 Fax: 33 1 60 13 37 06
Germany: 0208/31026 Fax: 0208/31441
Types: AC and DC
3. SensoTec, U.S.A.
Address Unknown
Phone: 1-800-848-6564
Fax 001-614-486-0506
Types: AC and DC
4. Macro Sensors (Division of H.A. Schaevitz Technologies !?!)
600 Main St.
Riverton, N.J. 08077-1419
USA
001 609 662 8000
Fax: 001 609 786 1939
Types: AC or DC
5. Omega
Leicester, U.K.
Phone 0455 285520
Fax 0455 283 912
Stevenege
0438 365671
Fax: 0438 356 203
6. Hottinger Baldwin Messtechnik GMBH
100 151, D-64201 Darmstadt
Im Tiefen See 45, D-64293 Darmstadt
Tel: 06151 803-0
Fax: 06151 894896
Types: AC
7. Micro-epsilon Messtechnik, Germany
+49 8542 168 0
Fax: +49 8542 16890
Types: AC only
Other Info:
-----------
There are alot of manufacturers around, but if you are looking for
a 12 V DC system there aren't too many options, and they're all about
the same price (approx $300/unit). In the end we ordered from Solartron.
A 10 Channel LVDT growth recording system is available from:
Mosaic Systems
P.O.Box 914,
Palmerston North
P.O.Box 8238
Auckland, N.Z.
Phone: 06 355 4196, 09 377 7963
Fax: 06 355 4197, 09 307 6763
I found out about two strain-guage systems that do the same thing
for a fraction of the price. One is described below in the digest
from Dynamax. A second is a ready to use dendrometer produced by
an Israeli strain guage company, but is not ready for marketing.
Notes:
Several people answered that they use Hewlett Packard LVDT's. From
my inquiries it seems that HP stopped manufacturing LVDT's and passed
along the manufacturing to Lucas Schaevitz.
Compiled and Edited by:
Shabtai Cohen, Ph.D.
EMAIL: vwshep at volcani.agri.gov.il
FAX: 972-3-9604017
PHONE: 972-3-9683698
Dept. of Environmental Physics and Irrigation
Institute of Soils and Water
A.R.O. Volcani Center
P.O.B. 6
Bet Dagan 50250
Israel
================================================
--------------------------------------------------------------
Edited messages in digest form:
--------------------------------------------------------------
From: WINS%"p.vangardingen at ed.ac.uk" 1-NOV-1995 16:33:35.06
From: Paul van Gardingen <PAULVG at srv0.bio.ed.ac.uk>
Organization: Edinburgh University
We have used quite a variety over the years but now tend to go for
the simple models that have DC input and output.
The ones we have used are manufactured by sangamo/schumberger. One
thing to check is that the ones that you choose are weatherproof.
Dr Paul van Gardingen Institute of Ecology
& Resource Management
E-mail: P.vangardingen at ed.ac.uk The University of Edinburgh
Phone: +44 (0)131 535 4066 School of Agriculture
West Mains Road
Fax : +44 (0)131 667-2601 Edinburgh EH9 3JG, Scotland
-----------------------------------------------
From: mryan at lamar.colostate.edu (Mike Ryan)
Rocky Mountain Experiment Station
240 West Prospect RD
Ft Collins, CO 80526-2098
(970) 498-1012 phone
(970) 498-1010 fax
ADC in England has "electric dendrometers" for measuring stem and fruit
expansion. Their address is adc.co.uk
ADC
Pindar Road
Hoddeston, Herts.
EN11 0AQ
England
fax: +44 1992 444567
---------------------------------------------------
From: WINS%"<S.J.M.Caporn at mmu.ac.uk>" 1-NOV-1995 18:49:42.83
From: "S.CAPONE" <S.J.M.Caporn at mmu.ac.uk>
Re:LVDT's
I have a research project with Dr Keith Parkinson of PPSystems (UK) to
develop a new instrument for measurement of extension of leaves. It
will be cheaper than LVDT's. My student Sam Jackson is working on
this; I will get her to send any marketing information as it becomes
available. Yours sincerely,
Dr Simon J.M. Caporn
Senior Lecturer in Environmental Biology
Division of Environmental Science
The Manchester Metropolitan University
Crewe and Alsager Faculty
Crewe Green Road
Crewe
Cheshire CW1 1DU
UK
---------------------------------------------------
From: WINS%"George.Koch at nau.edu" 1-NOV-1995 19:17:59.08
From: George.Koch at nau.edu (George Koch)
try Agricultural Electronics Corporation, P.O.Box 50291, Tuscon AZ 85703-1291
tel & fax:602 624 7656. William Gensler is the person to contact there.
I haven't used their products, but the specs. look good.
Dr. George W. Koch
Assistant Professor
Department of Biological Sciences
Northern Arizona University
Flagstaff, AZ 86011-5640
Tel: 520 523 7150
FAX: 520 523 7500
---------------------------------------------------
From: WINS%"<aphalo at cc.joensuu.fi>" 2-NOV-1995 09:00:24.82
From: "Pedro J. Aphalo" <aphalo at cc.joensuu.fi>
Organization: University of Joensuu
Some distributors which carry HP's LVDTs and/or "own brand" types are:
RS Components International.
Fax: +44 1536 204237
Fax them to find your local distributor and get
their free catalogue (LVDTs are in pages 854-856).
Get also their data sheet No. 9681.
Farnell Components used to sell HP's LDVTs but they are not in their
latest catalogue...
Pedro J. Aphalo
University of Joensuu, Faculty of Forestry
P.O. Box 111, FIN-80101 Joensuu, FINLAND
e-mail: aphalo at cc.joensuu.fihttp://www.joensuu.fi/~aphalo/
fax: +358 73 151 4444 (or +358 73 151 3590)
tel: +358 73 151 4406 ,,,^..^,,,
---------------------------------------------------------------
Thu, 2 Nov 95 10:51:05 EST
From: "Glyn Bengough" <CEPGB at scri.sari.ac.uk>
Lucas Schaevitz (in North America - 7905 N. Route 130 Pennsauken, NJ
08110, Fax 609/662-6281) supplies LVDTs and has European and North
American outlets.
Glyn Bengough
Department of Cellular and Environmental Physiology,
Scottish Crop Research Institute,
Dundee DD2 5DA, Scotland
Telephone: National 01382 562731 extension 2527
Fax: National 01382 562426 International +44 1382 562426
------------------------------------------------------------
From: WINS%"<morisj at essex.ac.uk>" 2-NOV-1995 21:00:10.08
From: Dr James I L Morison <morisj at essex.ac.uk>
IN the UK they are readily available through all general electronics
distributors, such as RadioSpares (RS). A quick look in the catalogue shows
a variety of high precision ones, around 100 pounds stlg; don't know what
source. I can enquire if you like. Schlumberger used to make them, I know.
James
Dr. James I.L. Morison,
Department of Biological and Chemical Sciences,
The John Tabor Laboratories,
University of Essex,
Wivenhoe Park,
Colchester CO4 3SQ
Essex UK
tel : +44 (0)1206 873327
fax: +44 (0)1206 873416
email : morisj at essex.ac.uk
http:://www.essex.ac.uk/biology/staff/jilm/jilm.htm
----------------------------------------------------------
Sun, 5 Nov 95 22:49:38 EST
From: "Trought, Michael" <TROUGHTM at whio.lincoln.ac.nz>
Organization: Lincoln University
I have just pruchased a 10 channel LVDT system from Mosaic Systems,
Palmerston North, based on a design prepared by Dr Sandy Lang,
HortResearch, Palmerston North. I am very pleased with the system.
I suggest that you contact Sandy: Slang at hort.cri.nz
Dr Mike Trought Telephone (64) (03) 325 2811
Department of Plant Sciences Fax (64) (03) 325 3843
PO Box 84 Internet Troughtm at Lincoln.ac.nz
Lincoln University
Canterbury
New Zealand
-----------------------------------------------------------
Tue, 7 Nov 95 11:05:31 EST
From: sja <S.Allen at unixa.nerc-wallingford.ac.uk>
I heard recently of a company in the USA who have started to
manufacture two systems (based on strain gauges) specifically designed
for accurately measuring the expansion of stems and fruits. The company
(Dynamax) is the same one which manufactures stem heat balance gauges
for measuring sap flow rates in plant stems.
Dynamac Inc.
9888 Bissonnet
Suite 150
Houston
Texas 77036
USA
Tel: +1 713-771-4224
Fax: +1 713-771-4102
The model codes for their 'electronic dendrometers' are DEX-70 and
DEX-100.
Simon Allen
Institute of Hydrology, UK
--------------------------------------------------------------
Wed, 8 Nov 95 00:36:08 EST
From: "Sandy Lang" <slang at hort.cri.nz>
Organization: Hort Research, Palmerston North, NZ
Email: SLANG at HORT.CRI.NZ
Mail: HortResearch
Private Bag 11 030
Palmerston North
New Zealand
Tel: +64-6-356-8080
Fax: +64-6-354-6731
----------------------------------------------------------------
From: WINS%"<CEPGB at scri.sari.ac.uk>" 9-NOV-1995 12:58:23.04
From: "Glyn Bengough" <CEPGB at scri.sari.ac.uk>
Date: Thu, 9 Nov 1995 10:55:38 GMT
Thanks for your email - the fax number is as written on the company
brochure. You could try the European number FAX +44 1753 823563 (if
dialing internationally).
(Lucas Schaevitz, 543 Ipswich Road, Slough, Berkshire, SL1 4EG).
Glyn Bengough
Department of Cellular and Environmental Physiology,
Scottish Crop Research Institute,
Dundee DD2 5DA, Scotland
Telephone: National 01382 562731 extension 2527
Fax: National 01382 562426 International +44 1382 562426
---------------------------------------------------------------
Mon, 20 Nov 95 12:37:50 EST
From: "Pieter van de Sanden, AB-DLO, Wageningen" <P.A.C.M.VANDESANDEN at ab.dlo.nl
I have been working with LVDT's measuring the
volume growth of individual tomato fruits (in response to root environment
water potential in aerohydroponics).
My LVDT's are from Schlumberger Transducers, Steyning Way, Southern
Cross Industrial Estate, Bognor Regis, Wets Sussex, PO22 9ST, UK. Phone
(0243)825011, Fax 861244 (address data dated 1990 !).
I used the ST200 type in combination with the CAH16 - 16 channel LVDT
conditioning PCB. If you are interested I can fax you some of the info-
leaflets I have on these equipment.
My personal experience: these sensors are very sensitive and as such can
give you information on a short time scale, but they are also very
temperature-sensitive. And the temperature-sensitivity is very hard to
calibrate, primarily since it is very hard to establish what temperature the
sensor is sensing. So, it is important to weight the advantage of sensitivity to
displacement against the sensitivity to temperature. Maybe next time I
would chose a less temperature-sensitive type and consequently a sensor
less sensitive to displacement. It is up to you to calculate from the research
question you want to answer what displacement resolution you need and
look for a sensor which has a temperature-sensitivity that does not override
the resolution/range you want to study. I have been working in a fytotron and
still there the climate control, especially dark/light transition, causes effects
which I am hardly able to describe to temperature or to fruit
contraction/expansion.
Pieter van de Sanden
Research Institute for Agrobiology and Soil Fertility
PO Box 14
NL - 6700 AA Wageningen, the Netherlands
E-mail VANDESANDEN at AB.DLO.NL
______________________________________________________________________
Peter Minchin, HortResearch,
Private bag 31-313, Lower Hutt, New Zealand.
ph: +64-4-5690-232 Fax: +64-4-5690-372 e-mail: PMinchin at hort.cri.nz
------------------------------------------------------
Dr David Yates
Botany Department
The University of Queensland
Brisbane, Qld, 4072
Australia
phone +61 7 3365 2070
fax +61 7 3365 1699
------------------------------------------------------
Moshe Cohen Aman
IRTA
Cabrils (Barcelona)
Spain
Cohen at cabrils.irta.es
