ISO 594 is Obsolete ISO 80369-7:2016 cancels and replaces the first edition ISO 594-1:1986 and the second edition of ISO 594-2:1998, clauses, subclauses, tables, figures, and annexes of which have been consolidated and technically revised.
Why only 5 Newtons of Force?
The origination of the requirement of 5-Newtons of force to be applied to Luer Ring Gages and Luer Plug Gauges is found in ISO 594/1 paragraph 5.1.4 where it states: Apply the gauge to the conical fitting with a total axial
force of 5 N, without the use of torque. Remove the axial load.
Since ISO 594 is obsolete; why do we care?
Because of the problems inherent with improperly interconnecting dissimilar medical devices ISO 594 was replaced with ISO 80369. With the change; focus on the specifications pointed toward functional testing of the connectors. There is still a need for the conical taper gauges, which are intended for in-process monitoring and receiving inspection, which provide a quick size test of the Luer taper cone. In-process monitoring and incoming inspection are not addressed in ISO 80369 and are left up to the individual manufacturer or purchaser. Even though ISO 594 is obsolete; Luer taper gages, with designs simular to the original ISO 594/1 design, are available for ISO 80369 Luer Conical Connectors.
Again I ask: Why is 5 Newtons of Force important?
It is a fact that the Luer taper allows for varying dept of insertion for mating pieces depending on the force and torque applied. This is good for in-use applications of the Luer connectors; but it wreaks havoc on repeatable testing results. To harmonize the test results from person to person; from company to company and from country to country the 5 Newton gage application force was instituted. By adhering to this historical force specification you will be maintaining consistency of your tests, and consistency is good for comparing test results.
Procedure for using the Figure 3x Ring and Plug Gages
The following data is extracted from ISO 594/1 and expanded
for further clarification.
5.1 Gauging Test: The procedure shall be carried out as specified
below in 5.1.1 to 5.1.4.
5.1.1 Carry out the test using steel gauge as illustrated
in ISO 594/1 Figure 3x.
5.1.2 Carry out the test at a temperature of 20°C +/-5°C.
5.1.3 Prior to testing, condition products made from hygroscopic
materials at 20°C +/-5°C and 50% +/-10% relative humidity
for not less than 24 hours. Conditioning is not required for
products made from non-hygroscopic materials.
5.1.4 Apply the gauge to the conical fitting with a total
axial force of 5 Newtons, without the use of torque. Remove the axial load.
4.1.1 Ring Gauging test results:
4.1.1.a. The small end of the male conical fitting shall lie between
the two limit planes of the gauge.
4.1.1.b. The larger end of the tapered portion shall extend beyond
the datum plane of the gauge.
4.1.1.c. Rocking shall not be evident between the gauge and rigid
material fitting undergoing test. This test for freedom from
rocking may also be found useful (not required) for evaluating
semi-rigid fittings.
4.1.2 Gauging test results:
4.1.2.a. The plane of the maximum diameter at the opening of the
female conical fitting shall lie between the two limit planes
on the gauge.
4.1.2.b. Rocking shall not be evident between the gauge and rigid
material fitting undergoing test. This test for freedom from
rocking may also be found useful (not required) for evaluating
semi-rigid fittings.
Disclaimer
This data is provided for general information only. The intention is to provide accurate information; regardless; errors may exist in the supplied information. If accuracy is critical, base your final decisions on the data provided in the root documents: ISO 594-1 which is a copyrighted document. To purchase a copy of these engineering document visit an Authorized Reseller.
Comments:
Original Posting: 12/2/2014
Last Revision: 1/16/2017
Error corrections in, or comments about, the above data can be sent to: office@gagecrib.com
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