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Latest News and Updates
(updated 13 February, 2009)

 

Chilworth Technology Acquires John Chubb instrumentation (JCI)

After more than 26 years of leading JCI to its current enviable position as a world recognised provider of high quality electrostatic measurement products, John Chubb has decided it is time to retire. He is therefore delighted that JCI has been acquired by Chilworth Technology Ltd.

Chilworth Technology Ltd, (CTL) is a leading provider of expert services in the field of process safety and electrostatics, currently with bases in 8 countries (including the USA and India), and its own worldwide reputation for excellence. In addition to process safety testing and consultancy, CTL already manufactures a range of specialist instrumentation, and is renowned for its expertise in the area of electrostatics. The JCI business therefore fits very well alongside that of Chilworth Technology, where it is expected that Chilworth’s direct presence, and experience in marketing around the world will lead to rapid growth.

For the full press release see here. For information on electrostatics consultancy and the JCI product range see the above menu options. Further information on the full range of process safety testing and consultancy services from Chilworth can be found at www.chilworth.co.uk. Other process safety laboratory instruments can be found on our Chilworth Systems website at www.chilworth-systems.co.uk.

"Tribocharging studies on inhabited cleanroom garments"

This paper reports studies that show there is little sgnificant difference in the surface voltages created at tribocharging of inhabited cleanroom garments whether these are made of fabrics that include surface conductive or core conductive threads. The fabrics with surface conductive threads show very acceptable values of surface resistivity (as expected) whereas those with core conductive threads show (as expected) very high values of resistivity - well above the levels usually considered acceptable. These studies therefore call into question whether resistivity is an appropriate measurement for assessing the suitability of garment materials.

This paper is published in J. Electrostatics 66 2008 p531-537 and is available online via: http://www.sciencedirect.com The test method used in the above studies is available on this Website.

JCI 504 Lightning Warning System

The JCI 504 system installed and commissioned on Benbecula in the Outer Hebrides at the end of last Augsust has been working well. This system is an updated version of the JCI 501 system that was installed on St Kilda 10 years ago and has been in continuous operation since then. Like the St Kilda system, this new one will enable more specific prediction to be made of the local risk of lightning occurrence than is available on the basis of meteorological data and the tracking of pre-existing lightning activity.

A full description of the system and its operation is presented in the user manual.

"An Introduction to Electrostatic Measurements"

The Notes that were prepared by John Chubb for the Introductory Workshops that have preceded the last three of the Institute of Physics 'Electrostatic Conferences' have been expanded and updated into a book. This is now available to download from this Website.

"A Standard proposed for assessing the electrostatic suitability of materials"

A paper outlining the philosophy of the test method developed at JCI for assessing the electrostatic suitability of materials is published in J Electrostatics 65 2007 p607-610. This test method is based on measurement of the corona charge decay and capacitance loading characteristics of materials.

A document proposing methods for the formal calibration of electrostatic measuring instruments has been offered to British Standards.

Charge calibration

A unit, the JCI 256, has been developed to enable virtual earth charge measurement circuits to be formally calibrated. The principle of operation is to have a current, that is defined by a reference voltage and a precision resistor, switched from a link to earth into the output connection for a time that is set by counting a selected number of pulses from a quartz crystal oscillator. The unit provides defined quantities of charge in the range 1nC to 999nC with a precision of 1%. Arrangements are included to enable the unit to be formally calibrated with reference to National Standards.  

Control of temperature in JCI 191C Controlled Humidity Test Chamber

Arrangements have been developed that enable the temperature for testing within a JCI 191 Controlled Humidity Test Chamber to be regulated to within half a degree C for external ambient temperatures both 10C below and above the desired test temperature. This facility enables testing to be carried out at 'Standard' levels (23C) in both warm or cool external conditions. Up to now the JCI 191 has only offered the opportunity to control temperatures above ambient - now we can offer a thermoelectric unit to also provide controlled cooling below ambient.  

NASA paper including studies with JCI 155 Charge Decay Test Unit

A paper has recently been published in Journal of Electrostatics by Charles Buhler and colleagues at the NASA Electrostatics and Surface Physics Laboratory at Kennedy Space Center on test methodologies for assessing materials. This paper includes descriptions of the JCI 155 and JCI 176 and how these are used to make measurements. It also includes comparative charge decay test results between corona charging measurements with a JCI 155 and results achieved with the NASA tribocharging test method. (J. Electrostatics 64 2006 p744-751)  

New version of JCI 140 Static Monitor

Recent enhancements to the signal processing circuits of the JCI 140 Static Monitor have enabled the signal to noise ratio and the basic frequency response to be usefully improved at the same time. Noise is now equivalent to less than 1V r.m.s. of surface voltage at 100mm over the frequency range to 100 Hz (-3dB at 120Hz). This performance enables the JCI 140 to now be used for monitoring both quasi-continuous voltages on surfaces and in space and also voltages that arise from 50/60Hz mains sources. The quasi-continuous readings are shown directly of the instrument display. Mains frequency observations can be displayed and measured as an a.c. signal on a Digital Multimeter or digital storage oscilloscope connected to the analogue output socket.

Combined measurement of atmospheric and power line electric fields:

A special version of the JCI 131 Adverse Conditions Electrostatic Fieldmeter has recently been supplied to 'Human Radiation Effects Group' at the University of Bristol. The frequency reponse of the fieldmeter was enhanced to -3dB at 70Hz with adjustments to the operational health system to avoid cross interaction between field and health observations. The new version Base Unit, the JCI 234, uses a low pass filter (-3dB at 7Hz) for direct measurement and display of quasi-contiunuous atmospheric electric fields and a bandpass filter followed by a precision rectifier for measurement and display of power line frequency fields.

Company incorporation:

As from 1 May 2006 John Chubb Instrumentation has become a Limited Liability Company (Company registration number 5978844). Business activities, location and contact addresses remain just the same as for JCI.

Studies on Solvent Extraction (SX) plants:

In January and in March this year further studies were carried out at copper mines in Laos and in Chile on electrostatic safety aspects of operating solvent extraction plants. It is hoped to report general conclusions on requirements for safe operation at the Institute of Physics 'Electrostatics 2007' Conference in Oxford, March 2007.

Distributor for Taiwan:

JCI has appointed Hong Cheng Technologies Co as the Distributor for JCI instruments in Taiwan. The range of JCI instruments complements the range of Monroe instruments already being sold by Hong Cheng. (3F-5, No.26, Tai Yuen St., Chu-Pei City, Hsing-Chu Hsien, Taiwan Tai Yuen Hi-Tech. Industrial Park Tel: (03) 552-6071 Fax: (03) 552-6073 Website: http://www.hongcheng.com.tw email: hong7039@ms61.hinet.net)

"Electrostatic safety during solvent extraction"

Paper by John Chubb and Graham Hearn presented at 'Centre for Separation Technology' Workshop at Lappeenranta University of Technology, Lappeeranta, Finland 8 & 9 August, 2005

"Large scale Faraday Pail JCI 247"

The JCI 247 Faraday Pail is for measuring charge on larger scale items than can be done with the JCI 147 Faraday Pail. As with the JCI 147, it can also be used with liquids and powders. The pail is 300mm diameter 4 90mm high within a shielding enclosure 460mm diameter and 580mm tall with a 260mm diameter sample entry aperture. Charge introduced into the pail is measured using, for example, a JCI 178 Charge Measurement Unit with 20nC and 200nC ranges of sensitivity and the ability to resolve to 10pC.

"Non-contact measurement of shielding and the resistivity of layer materials"

Paper submitted for publication in J. Electrostatics, Aug 2005. This paper reports studies using the method of assessing shielding performance, developed at JCI, involving measurement of the variation of shielding with frequency. Measurements are reported showing how the variation of shielding performance with frequency reveals the effective resistivity of layer materials. The special advantage of the approach is that it is non-contact and non-invasive.

Update of JCI-Graph

JCI-Graph has recently been updated to enable variations of local decay time constant values to be displayed with a linear, as an altentative to a quasi-logarithmic, axis. This facility makes it easier to appreciate the apparently linear variation of time constants with time during the progress of charge decay. For materials showing very slow charge decay (e.g. some pharmaceutical powders) this will make it easier to predict the time to achieve certain end points within modest periods of testing.

"Measurement of charge transfer in electrostatic discharges"

Paper to be published in J. Electrostatics Studies have recently been carried out that confirm the need to use shielded probes to measure the quantities of charge transferred and the currents involved in electrostatic discharges. (These studies support the arguments made by John Chubb and John Butterworth in a Journal of Electrostatics paper in 1982 13 p209). A paper on this new work has been submitted to Journal of Electrostatics.

Electrostatic ignition risks and tank washing operations

A paper about the ignition risks that can arise during the washing of cargo tanks on large crude oil tankers with high pressure water jets. Toftejorge Website (http://www.toftejorg-tech.com/sw7663.asp) Dec, 2004

Method for testing the electrostatic suitability of materials

A draft document has been prepared that describes a method of testing the suitablility of materials by a combination of charge decay and capacitance loading measurements. This document has been offered to British Standards as a prospective new Standard test method.

Tribo and corona charging comparison:

Experimental studies have been carried out that show a good correspondence of charge decay time and capacitance loading characteristics between tribo and corona charging for a variety of materials. The materials were chosen with performance features over the range of practical interest.

T he studies have drawn attention to the point that that surface charge separated at tribocharging only comes to exert local electrostatic influence around 100ms or so after the end of the charging action - at separation of the surfaces. Thus in corona charge decay studies to assess the suitability of materials to avoid problems it is actually the voltage at this time that should be used for calculating capacitance loaidng values and to form the initial voltage for charge decaytime measurements. The decay of surface voltages before this time is hence only of technical interest - not of practical relevance.

Comments on methods for measuring 'Charge Decay':

There are a number of methods used for measuring 'charge decay' to assess the suitability of materials. Several are 'Standard' methods. They give quite different results - so they cannot all be right! These personal comments highlight the differences in the approaches and point out deficiencies. (This paper has now been published in J. Electrostatics 62 (1) 2004 p73-80).

Assessment of materials:

Letter to the Editor, ESD Association Newsletter "Threshold" July/August 2003 p10 and on-line 'ESD Journal'.

Standards:

Some personal comments on the preparation of 'Standards' in electrostatics. (Also on Website of 'Electrostatics Society of America')

Studies of electrostatic safety during solvent extraction of copper:

Investigatory studies were carried out on electrostatic safety duirng in the so lvent extraction plant of the largest open-cast copper mine in the world - the Codelco Chile - Radomiro Tomic plant near Calama in north Chile. This work was carried out 2 to 4 June 2002 for Ingenier’a y Desarrollo Tecnol—gico S.A. (IDT) of Santiago in Chile.

This work was described in a paper at the 'Electrostatics 2003' Conference at Heriot Watt University, Edinburgh 23-27 March, 2003 "Electrostatic safety during the solvent extraction of copper". (This paper is to be published in J. Electrostatics).

The studies showed that with the solvent and extractant liquids used there are no risks of electrostatic ignition in normal plant operation. This is despite the extensive use of HDPE pipework. Safety depends upon rapid relaxation of electrostatic charge within the process liquids. Charge decay times were measured to be in the range 0. 025 to 0.030 seconds for both the loaded and unloaded liquids.

JCI 134 Base Unit for JCI 131 Adverse Conditions fieldmeter.

A number of new units have been added to the list of JCI products to assist measurement of atmo spheric electric fields by JCI 131 fieldmeters. These include the JCI 134 Base Unit, to provide mains or battery power supplies and display of observations, the JCI 137 Mounting pole, to support the JCI 131 about 2m above ground and the JCI 136 100m extension cable to link the fieldmeter to a remotely positioned Base Unit. Also available is the JCI 133 operational health facility for contiunously monitoring and reporting of operational health status to the JCI 134 Base Unit.

JCI 155 at NASA:

A JCI 155 Charge Decay Test Unit is in use for assessing materials at the Electrostatics and Surface Physics Laboratory of NASA Kennedy Space Centre in Florida.

Enhanced performance of JCI 140 Static Monitor instruments:

Recent enhancements to the circuits of JCI 140 Static Monitor instruments have improved stability of readings to better than a volt and reduced noise on analogue output signals. The frequency response of fast response version i nstruments (JCI 140F) has been increased to 400Hz. Zero and signal output noise are within 2mV peak to peak - equivalent to 2V of surface potential at 100mm.

Product leaflets:

Descriptions of several JCI instruments are now available on this Website in Adobe Acrobat .pdf format as is a version of the List of Products. This makes it easier to print the leaflets and list with good presentational layout..

JCI 155v6 Charge Decay Test Unit:

The JCI 155v6 Charge Decay Test Unit provides easy assessment of the suitability of materials for avoiding problems from static electricity in terms of the time for charge decay and the capacitance experienced by charge on the surface. This approach is the subject of a new Test Method that is progressing to become a British Standard.

The new instrument is basically similar in operation to earlier JCI 155 instruments but has the special feature of an integral microprocessor. This enables all basic analysis, display and storage of charge decay curves to be carried out by software within the instrument. Observations are stored to a PCMCIA memory card (or CompactFlash memory in a card adaptor) that can be slot ted into the instrument and can be read, processed and displayed off-line in a microcomputer running proprietary Windows software JCI-Graph . A version of JCI-Graph is now available that also provides for direct on-line operation of JCI 155v6 i nstruments with quasi real time display of charge decay observations.

The integral software provides full versatility in setting instrument operation and the measurement arrangements (see JCI 155v6 User Manual). Instrument operating parameters have default values and these can be modified using the push buttons to select and edit parameter values ? for example, the corona voltage and duration, the conditions for ending a run by maximum time or by reaching a set voltage level and whether the plate is retracted quickly (20ms), for fast decay time measurements, or slowly, for measurements on light powders with minimum sample disturbance.

The corona charge transferred to samples in operation of JCI 155v6 instruments can be directly measured using a JCI 176 Charge Measuring Sample Support. Measurements on powders and liquids can also be made using a JCI 173 Powder Sample Support Plate between the mounting plates of a JCI 176.

A recent update to the instrument has been to move the mains power supply unit outside the instru ment and to provide light ventilation through the instrument when operated from the external power unit. This has been done to reduce the slight heating within the instrument so that internal temperature and humidity are a good match the the surrounding ambient conditions.

JCI-Graph

This software enables charge decay observations, recorded from operation of JCI 155v4, as well as JCI 155v6 instruments, to be processed and graphed within a Windows 95/98, 2000, NT or XP operating environment. It also enables obsrevations recorded using a 'Picoscope' digital storage oscilloscope to be displayed.

The latest version of JCI-Graph enables JCI 155v6 instruments to be operated with direct serial data linkage to a PC. This provides basic control of instrument operation and enables charge decay graphs and associated test data to be displayed directly in near-real time. This is very useful when measurements are being made in situations where it may not be easy to read the instrument display or control instrument operation.

Charge decay graphs and details of test results and conditions can be displayed, manipulated and transferred into other Windows applications - such as Word documents. (The User Manual for JCI-Graph is available on this Website.

JCI 255 Calibrator Unit

For formal calibration of JCI 155v4 and JCI 155v6 corona charge decay measurement instrumentation. Calibration involves two pa rts: calibration of the voltage sensitivity of the fieldmeter and calibration of the decay time measurement performance. The JCI 255 Calibrator unit enables these two aspects to be formally calibrated to the procedure set out in BS 7506: Part 2: 1996 using measurements whose accuracy is traceable to National Standards.

Recent publications:

A number of articles have been written on work to measure the surface voltages that can arise on inhabited cleanroom garments when rubbed, and how well this electrostatic performance of garments may be predicted from charge decay and capacitance loading measurements on sample areas of garments or garment fabric.

A paper was presented at the EOS/ESD 25th ANNUAL SYMPOSIUM in Las Vegas 21-25 September, 2003: "Test procedures for predicting surface voltages on inhabited garments" by Paul Holdstock (BTTG), John Chubb (JCI), Michael J D Dyer (Barnet).

A paper "Predicting the maximum surface voltages expected on inhabited cleanroom garments in practical use" with Paul Holdstock (BTTG) and Mick Dyer (William Barnet and Son Inc) was presented at the ESTECH 20 03, Contamination Control Division meeting in Phoenix, Arizona.18-21 May, 2003.

A paper "Predicting the maximum voltages expected on inhabited cleanroom garments in practical use" with Paul. Holdstoc k (BTTG) and Mick Dyer (William Barnet and Son Inc) was presented at the Institute of Physics 'Electrostatics 2003' at Heriot Watt University, Edinburgh, 23-27 March, 2003.

"Assessing the influence of electrostatic charge retained on materials" 'Compliance Engineering' 2002 Reference Guide p124 'Can cleanroom garments create electrostatic risks?' was published in 'Cleanroom Technology' March, 2002 and is available in the on-line ESD Journal.

A second article "Can one predict the surface voltages that will arise on cleanroom garment by tribocharging?" shows that prediction is indeed feasible. This article is available on this Website and in the on-line ESD Journal.

A Test Method we have developed for measuring the surface voltages that arise by tribocharging on inhabited cleanroom garments is available. The procedure we have developed for predicting the maximum surface voltages to be expected on inhabited garments isavailable as a PowerPoint presentation and as a document . This work was presented at the ESTECH Conference in Phoenix, Arizona in May.

(There is a Website available that provides a wide range of information sources and linkages about textiles)

"COMPANY PROFILE" A profile of John Chubb Instrumentation has been presented in the on-line 'ESD Journal'.

ELECTROSTATIC MEASUREMENTS The Institute of Physics, Static Electrification Group arranged a meeting on 'Electrostatic Measurements' on 13 November, 2001 at the Institute of Energy, Devonshire Street, London. The programme for this meeting was arranged by Dr Paul Holdstock, British Textile Technology Group (email: pholdstock@bttg.co.uk). A paper on "Measuring the electrostatic suitability of materials" was presented by John Chubb.

An article "Cleanrooms and static" has been published in 'Cleanroom Technology' (Polygon Media Ltd), October 2001 p30

IEEE-IAS 1999 meeting Phoenix, Arizona: The paper presented by John Chubb at this meeting, 3-5 October, 1999: "Measurement of tribo and corona charg ing features of materials for assessment of risks from static electricity" has now been formally published in IEEE Transactions on Industry Applications 36 No 6, Nov/Dec 2000 p1515-1522. The paper as presented at the meeting and the overhead slides are available on this Website.

'2000 IEEE, Rome': A paper "Measuring the shielding performance of materials" was presented at the '2000 IEEE-IAS' meeting in Rome, 8-12 October. (Click here for overhead slides presented). An article based on this paper "How effectively do materials shield against transient electric fields?" is published in IEEE Ind Appl Magazine 8 (5) Sept/Oct 2002 p13. This paper is to be published formally in IEEE Trans Ind Appl later this year.

'ESA 2000', Niagara Falls: Two papers were presented at the Electrostatics Society of America 'ESA 2000' meeting, Niagara Falls, June 18-21 , 2000: "New approaches for electrostatic testing of materials" and "A system for the advance warning of lightning" The paper on testing materials was published in 'Journal of Electrostatics' 54 March 2002 p233.

'Packaging Technology' & 'Bulk Handling': An article "Resisting the charge" has been published in 'Packaging Technology' May/June 2000, p13 and an article "FIBC ignition risks from static electricity" in 'Bulk Handling International', May/June 2000, p25

Lectures in Helsinki: John Chubb gave two lectures in Helsinki 4 May, 2000 as part of the STAHA programme of VTT Automation. Notes prepared for these lectures 'Electrostatic measurements: Opportunities and problems' and 'Electrostatic measurements: Applications' can be found on the VTT Automation Website as well as the JCI Website (access via Sitemap).

ESD Symposium:

John Chubb attended the 1999 Symposium in Orlando, Florida at the end of September as co-author, with Paul Holdstock (BTTG), of the paper presented by Ray Gompf (NASA) "Electrostatic test methods compared".

Charge decay studies: Studies with the JCI 155 have shown that the decay of corona charge correlates well with the decay of triboelectrically generated charge. This supports the JCI 155 approach for assessing the ability of materials to dissipate static electricity. Studies have also shown lack of damage by the use of corona - and lack of any relation of decay time to resistivity. The JCI 155 approach is now used quite widely in industry, especially in relation to fabrics (for instance by Marks and Spencer for assessing fabrics for low cling lingerie) and by a number of pharmaceutical companies. Some comments on the validity of corona charge decay measurements are included on this Website. Also included are some comments on methods of charge decay measurement in use.

The corona charge decay method for assessing materials is described in a new draft IEC Technical Report: IEC 61340-5-1: 1998 "Electrostatics - Part 5-1: Protection of electronic devices from electrostatic phenomena - General requirements". (JCI versions of the ways to measure charge decay and capacitance loading of static charge retained on surfaces are included on this Website).

'Threshold': Letter to the Editor EOS/ESD Association Newsletter 'Threshold' July/August 2001 in response article by Niels Jonassen in May/June 2001 issue of 'Threshold' "Comment: Voltage on insulators IS meaningful!" . Another letter to 'Threshold' was published in the January/February 2000 issue (p6): "Chargeability and influence of surface charge";

JCI instruments and facilities:

JCI 140 Static Monitor: Experience with PC based digital data recording shows great advantages for viewing and storing electrostatic observations with JCI 140 Static Monitor instruments. Observations can be made to the full fast response capability of JCI 140F instruments and the data logging capability provides opportunity for detailed monitoring of long term observations. Picotechnology, for example, provide compact and low cost units with both digital storage oscilloscope and datalogging facilities via a PC. The software is Windows compatible. (With these ne w opportunities for direct display and recording od observations the C option for JCI 140 instruments has been discontinued).

For long term continuous observations, JCI 140 and JCI 140F instruments may be powered from an isolated 12V regulated d.c. supply via a 2.1mm d.c. connector in the instrument back cover. (Suitable 12V 'wall cube' units are available from JCI as the JCI 142).

The following attachments are available for JCI 140 instruments:

JCI 145 Air Ionisation Test Unit : for measuring the ability of air ionisation to dissipate static

JCI 147 Faraday Pail: for measuring charge on items, powders and liquids with resolution to 1pC

JCI 148 Electrostatic Voltmeter: for measuring discrete voltages (for example on people) with negligible current drain up to 20kV. The input impedance is around 1015ohms to over 15kV and the self capacitance is about 7pF.

Lightning Warning Systems:

A JCI 501 system was installed and commissioned on the island of St Kilda (about 40 miles off the outer Hebrides into the Atlantic!) during June 1998. The system has worked well for over 9 years of essentially continuous operation. Warnings are based upon simultaneous observations of atmospheric electric field, of radio noise at 27kHz and of impulse signals over a 2-200kHz bandwidth. The analysis, display and storage of observations is carried out with a microcomputer with opportunity for full detail review of observations over the preceding 24 hours and long term data achieving to optical disc. Atmospheric electric field measurements are made using a JCI 131 fieldmeter. These measurements and the radio signal o bservations included continuous direct operational health monitoring to show continuing satisfactory operation of the equipment in the adverse weather conditions usual on St Kilda.

A new JCI 504 Lightning Warning System has been developed from the original JCI 501 system. This provides the same capabilities as the original JCI 501 system but with th advantage of enhancements to the Sensor Unit and incorporation of the microcomputer into the Base Unit for analysis and display of observations.

Charge and discharge measurenents:

JCI 178:An easy to use charge measurement unit has been developed for sensitive and stable measurement of charge transfer. This uses the basic JCI 140 type casing with most JCI 140 output facilities: analogue output signal matching liquid crystal display, battery operation. Sensitivities of 20nC and 200nC full scale. Instrument and remote zeroing and sensitivity setting. BNC input connection.

A hemispherically ended discharge probe, JCI 179, can be mounted d irectly on the BNC input connector of the JCI 178. This enables measurements to b e made with a shielded probe of the quantities of charge transferred in low energy electrostatic spark discharges.

Sample Supports for JCI 155 Charge Decay instrume nts:

The JCI 176 sample support unit enables measurements to be made of the quantitiy charge transferred to samples during charge decay testing with JCI 155 Charge Decay Test Units from 0.2 to 200nC. Combination of such measurements with measured values of initial peak voltage enables values of 'capacitance loading' to be calculated.

Powder and liquid samples can be mounted in a JCI 173 Powder Sample Support Plate between the mounting plates of a JCI 176. This enables measurements to be made of the quantities of charge transferred and estimates of capacitance loading for these materials.

A simple Support Plate, JCI 172, is now available to help measurements on light powders with the JCI 155 and the JCI 170 Powder Sample Support. The unit provides a simple stand-off of the powder surface from the JCI 155 test aperture to avoid risk of ingesting powder into the JCI 155 mechanics at movement of the air dam.

Controlled Humidity Test Chamber The JCI 191 Test Chamber enables charge decay and capacitance loading measuremen ts to be made at controlled and de fined humidities from above ambient down to below 15%RH. The chamber is big enough (800x600x300mm) to contain JCI 155 and JCI 176 instruments (or a JCI 149 and JCI 170) and a variety of samples. 'Glove box' gloves allow sample changing and mounting, as well as instrument control and adjustment, under low humidity conditions. A Dry Air Supply Unit (JCI 192) has recently been added to the product range. This provides a convenient source of very dry air (-40C dewpoint) for operation of the JCI 191 test chamber.

JCI 131 Adverse Conditions Fieldmeter:

The JCI 131 covers the need for long term continuous measurement of electric fields with good precision and reliability in adverse environmental conditions - such as measurement of atmospheric electric fields even during periods of heavy rain. It provides sensitivity ranges of 2, 20, 200 & 2000 kV m-1 FSD. Options include the continuous operational health monitoring arrangement (developed for the JCI 501 Lightning Warning System above) and a serial data interface.

A system for measuring vertical and horizontal components of atmospheric electric fields has recently been supplied to a customer. This uses two JCI 131 instruments mounted at either end of a 2m horizontal cross arm that ca n be elevated up to 4 1/2m on a telescopic mast. To enable measurements of horizontal electric field components to the best resolution of the JCI 131 fieldmeters (better than 1V m-1) the whole mast assembly is servoed to the average local potential observed by the two fieldmeters. (See "Use of fieldmeters to measure atmospheric electric fields"

Sales:

In the UK JCI sells directly to customers and also via AEA Technology ?Stat Attack?, Chilworth Technol ogy, Wolfson Electrostatics, Vermason and Static Safe Environments. Export sales (at around 40% of total) are achieved via: Monroe Electronics (USA), Swedish Electro Static AB (exclusive for Sweden, Denmark, Norway and Finland), Estion (Germany) and Suzhou CEP Co., Ltd in the People's Republic of China. (See Product list for contact details).

Monroe Electronics instruments:

JCI is the Monroe distributor in the UK. These instruments provide special capability for fast and accurate non-contact measurement of surface voltages, for measurements in flammable atmospheres and for the measurement of resistance and resistivity. A new instrument, recently introduced, is the Model 287 Ioniser Performance Analyser.

Consultancy:

Studies and special electrostatic measurements (including charge decay studies) are carried out in relation to a wide variety of static problems for customers in many different industries both at JCI premises and at customer plant.

Meetings:

Information about meetings likely to be of interest to people involved in electrostatics are listed on the Meetings page of this Website. This list includes direct linkages to We bsites for the Institute of Physics , the Journal of Electrostatics, etc. Contact the IoP, or the organisers listed, for details of individual meetings (IoP Tel: +44 (0)20 7470 4800 Fax: +44 (0)20 7470 4900).

STATIC AND PACKAGING: A meeting of the Printing, Packaging and Papermaking Group of the Institute of Physics in London, in conjunction with the Electrostatics Group, discussed the relevance of static electricity to packaging. The programme and abstracts for this meeting are available on this Website. The overhead slides for the Introductory Comments and about the assessment of materials by John Chubb are also available.

Electrostatics Conference:

The 'ELECTROSTATICS 1999' Conference, 29-31 March, 1999 was held at Homerton College, Cambridge. It was attended by over 150 delegates. The Conference Proceedings has been published by the Institute of Physics (Confr Series 163).

The 'ELECTROSTATICS 2003' This Institute of Physics International Conference was held March 23 to 27, 2003 at Heriot Watt University in Edinburgh as part of the 'Physics Congress'. The Conference was preceded on the Sunday (23 March) by a 1 day 'Introductory Workshop'.

A general overview on static electricity and relevant methods for its measurement is available on this Website as: "An Introduction to Electrostatic Measurements". This is an enhancement of the Notes prepared for the: 'Introductory Workshop in Electrostatics' that preceded the 'Electrostatics 2003' Conference held at Heriot Watt University, Edinburgh.

Useful Websites:

Published papers:

A general list of papers published by JNC on electrostatics is included in the JCI Website.

Papers included on the JCI Website include the two papers presented at the ?Static and Textiles? meeting in Brighton on March 18,1998 "Studies of charge transfer, peak voltage and charge decay on a variety of materials" and "The control of body voltage getting out of a car". There is also the pa per as presented at the IEEE-IAS meeting in Phoe nix, Arizona October, 1999: "Measurement of tribo and corona charging features of materials for assessment of risks from static electricity". The overhead slides presented are also available on this Website.

A paper has been published in the on-line ESD Journal Website "The control of risks from static electricity"



Chilworth Technology Ltd,
Beta House, Southampton Science Park, Southampton, SO16 7NS, UK
Tel: +44 (0)23 8076 0722 Fax: +44 (0)23 8076 7866
email: jchubb@jci.co.uk

© Chilworth Technology Ltd.