Company Profile-- Spotlight on
Chubb Instrumentations is located in Cheltenham in
the UK. Cheltenham is on the British Isles between Birmingham and
Anglo-Saxon settlement, Cheltenham - possibly from Celtenhomme,
'the town under the hill' - was the site of a monastery as early
as 803. Alfred the Great wrote admiringly of the peace of the settlement
on the banks of the River Chelt, and by the 13th century Cheltenham
was noted for its fairs and markets.
Cheltenham? John previously worked in Cheltenham and knew there
were a number of good people in the area. Having family in Birmingham,
Cheltenham and Bristol, he knew he couldn't go wrong with Cheltenham.
John states that, "there are good technical and professional
resources there, good communications by road and rail and a nice
town with plenty of cultural activities of various sorts during
The business of John Chubb Instrumentation
is electrostatic measurements. This incudes the development,
manufacture and marketing of instruments as well as test and consultancy
work for customers.
Chubb set up JCI in September 1983. John had worked in a variety
of areas over the years - electrostatic aspects of dust collection,
high power vacuum interrupters, cryopumping of hydrogen on helium
cooled surfaces, Monte Carlo modeling of free molecular gas flow.
With the aim to provide high quality, high performance instrumentation
for electrostatic measurements as well as consultancy in electrostatics,
JCI was formed.
"Electrostatic measurement was an area I had involvement with
from time to time from my PhD (behaviour of airborne particles in
corona discharge fields) though the tanker work at Culham Laboratory
for the Uk Atomic Energy Authority and in the work in North Wales.
I realised that although there was various instrumentation available
for electrostatic measurements much was of poor quality with only
a limited range of capability from any one supplier."
first product was the JCI 101 electrostatic fieldmeter.
This provided much higher useable sensitivity than was available
elsewhere. Attachments were soon added to enable this basic electric
field measurement capability to be used to measure charge, with
the JCI 151 Faraday Pail, and to measure discrete voltages,
with the JCI 148 electrostatic
voltmeter. Starting in 1987, JCI developed the JCI 155 Charge
Decay Test Unit. Work since then has been enhancing the performance,
ease of use and facilities of instrumentation based on these early
designs. All the product development work has been supported by
a good deal of investigative work that has been reported at conferences
and in published papers.
John states that, "Our products
aim to provide the capability to people in industry and research
to measure a wide range of electrostatic parameters with ease, confidence
and good precision. Our products cover the need to measure electrostatic
conditions (electric fields, charge, surface and volume voltage,
surface and volume charge density) and to assess the suitability
of materials (charge decay time and capacitance loading). Some instruments
have been developed for use in adverse
environmental conditions (JCI 131 fieldmeter, JCI 501 Lightning
Warning System). We have not developed instruments that are
already widely available, but on those that we feel provide approaches
that are appropriate measurements. (For this reason we do not make
any resistance or resistivity measuring instruments - there are
plenty around and they do not provide the information needed to
assess the suitability of materials!). Our instruments are used
in a wide variety of industries all over the world by specialist
and non-specialist staff and their performance is backed by a formal
calibration service (see BS 7506: Part 2: 1996)."
John Chubb Instrumentation
Unit 30, Lansdown Industrial Estate
Gloucester Road, Cheltenham, GL51 8PL
Tel: +44 (0)1242 573347
Fax: +44 (0)1242 251388
JCI Developments :
- Electrode configurations for magnetic
movement and electrostatic containment of arc roots in high power
- Studies of the variations of sticking coefficients and vapour
pressure of hydrogen condensed on liquid helium cooled surfaces.
- Monte Carlo modelling of free
molecular gas flow in complex vacuum systems
- Concept and demonstration of novel
monitor for respirable size airborne fibres
- Development of electrostatic 'field
mill' fieldmeters which do not require earthing of the rotating
- Development of instrumentation
for charge decay measurement
- Demonstration of comparable charge
decay performance betwen corona and tribo charging
- Proposal of concept of 'capacitance
loading' as an additional way to assess the electrostatic suitability