1. ispark 'i' Explosionprotection made by PTB:
a method for computer aided assessment and design of intrinsically safe circuits with Lo and Co -
Ik_000.PPT
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin

2. ispark 'i' User target group
Operators of sites requiring explosion protection
Manufacturers of explosion protected apparatus
Third party experts
Testing and certification bodies
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
104

3. ispark 'i' What does the method provide?
On the base of preset electrical source data, intrinsic safety of the source itself is checked and maximum permissible capacitances Co and inductances Lo are determined, specialities of cable reactances are picked up, granting some more headspace for site installations
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
100

4. ispark 'i' How does it work?
Systematic investigation of experimental ignition testing results, using the standardized spark test apparatus, yielded characteristic electrical and calorical parameters.
A computer program uses these parameters for a model based calculation
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
110

5. ispark 'i' Competing methods
practical use of the standardized spark test apparatus
analytical evaluation against reference ignition data according to IEC
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
114

6. 'i'
Disadvantages of practically using the standardized spark test apparatus
the standardized spark test apparatus itself, including appropriate infrastructure, is required
usage is prone to errors and often lengthy
experimental results are dependable only if statistically analysed, the standardized type test reveals no real significance
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
119

7. ispark 'i' Drawbacks using reference ignition data
reference ignition data are available only for some very simple sources and circuits
certain effects are not comprised by those data, for example non linearities and cables
usage is prone to error and often lengthy
reference ignition data often reveal quantita-tive contradictions
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
121

8. ispark 'i' Advantages using ispark
arbitrary electrical sources can be assessed
circuits comprising both, inductances AND capacitances as well as cables, are included
the application is simpliest to use
reproducibility and coherence are very high
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
140

9. ispark 'i' What kind of data must be preset?
zone 0,1 resp. zone 2 (safety factor 1,5 resp. 1,0)
gasgroup
type of circuit including quantities
for multiple sources parallel and/or serial con-nection
type of freewheeling if any
Cable data: L‘, C‘ and R‘
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
150

10. ispark 'i' What kind of data are reported? summary of preset data
if the source is determined intrinsically safe, a list of maximum Lo/Co pairs which are per-missible concurrently within the circuit
if inclusion of cables is claimed, additionally to Co/Lo pairs, a maximum cable length extra allowed
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
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11. ispark 'i' What's needed to use ispark?
personnel for type in electrical data and handle the reported results
a common standard PC running at least Win2000 (upto Win7_64)
the program package ispark itself
a license granted by PTB (royalty is € , halved for acknowledged certification bodies)
Note: License includes all subsequent impro-vements/versions of ispark without additional charge
ispark -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
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12. 'i' ispark‘s status today?
in PTB using ispark is the first choice when assessing circuits for certification
about one-third of European Notified Bodies have a license for ispark
as well as one-third of IECEx participants
weaknesses of standardized experimental type testing nowadays are found more and more -
Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
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13. ispark 'i' For further information please contact
Martin Krämer, Dipl.-Ing., Ag 3.62
Physikalisch-Technische Bundesanstalt
Bundesallee 100
38116 Braunschweig, DEUTSCHLAND
tel: (+49) 0531/
fax: (+49) 0531/
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Physikalisch-Technische Bundesanstalt Braunschweig und Berlin
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