IEC 61010-1 and Flammable Liquids

[ilkkahoo]

Hello everyone,

it's my first thread at this forum.

I am seeking tips related to IEC/EN 61010-1:2010 standard, clause 9.5 "Requirements for equipment containing or using flammable liquids".

The device is an electrical laboratory instrument that measures a property of liquid sample.

The simplest solution to bypass the clause would be to prohibit use of flammable sample liquids with the instrument. However, that is not ideal from business perspective. Sometimes customers will want to use liquids that are classified as flammable, such as ethanol.

Clause 9.5 offers three options to pass the clause:
a) temperature of sample liquid and materials contacting the liquid is limited to T+25 Celsius where T is fire point of liquid
b) quantity of liquid is limited to amount that does not cause spread of fire
c) fire enclosure

Option c) is ruled out at this point due to design. Option a) might be possible to implement as instruction for users, but liquid fire points are not generally listed at MSDS per my knowledge. Also this would rule out some flammable sample liquids, at least high concentrations of ethanol where the fire point is about 30 Celsius.

So I am left wondering how to verify conformance to option b). In a worst-case scenario the sample liquid volume could be 70 milli-litres, but that is more than enough for successful measurement. 10 milli-litres is a minimum needed for the measurement. Standard laboratory glass beakers are used as sample vessels.

Does anyone have experience with flammable liquids with similar instruments? How will a test laboratory verify conformance with clause 9.5b) ?

I highly appreciate any hints you might have.

 

[Kevin Mader]

Hi ilkkahoo,

I don't have direct experience with your problem, but I've cleared a number of lab type equipment under IEC61010-1. My suggestion here is to contact your safety folks (UL, METLabs, etc....whoever you use) and talk it through with them. They have the experience and possible solutions (design) that might help you achieve what you desire relative to you customers' usages.

I've found them helpful over the years and most are willing to do the work upfront for no/little out of pocket expense (especially if you end up doing the testing/retesting with them in the near-term). And it's a great way to set the right expectations for all parties going forward.

Good luck!!

Kevin