You can buy hydrogen sulphide from the major gas suppliers, such as BOC and Air Products (other suppliers are available!). You need to make a decision on the size of the gas bottle. Small gas bottles are easy to carry around. You will also need a regulator. Gas bottles are normally rented from the gas supplier, and you pay for the gas. When it is empty, the bottle is replaced with a new one, for which again you pay for the gas.

I would definitely not advocate carrying around a bottle of hydrogen sulphide in the back of a van, even in a van where the goods compartment is entirely isolated from the driver.

p.s. The sensor JJ Prendergast is based on a fuel cell and of the type I sued to make - that's the sort I'd go for! p.p.s I agree with Jane - I wouldn't want a cylinder of H2S in my boot :)

I a gree with the above, there are hundreds of H2s detectors available that you don't need to have a H2s bottle to use and you only need to send them away periodically to calibrate. I have always found the MSA ones to be reliable but there are many others on the market

Calibrated gas bottles are used across industry to calibrate and 'bump' test portable and transportable gas detection equipment. Most bump tests are carried out using a methane/air mixture for testing the serviceability of catalytic flammable gas detectors but should you wish to confirm the serviceability of your H2S detector, a standard test gas with an appropriate level of gas should be used (typically 25 or 40ppm H2S). Other members have commented on carrying this substance as it is obviously dangerous and I agree, all precautions should be taken to avoid inadvertant release, especially when kept in vans as a concentrated release at these values will cause coughing, eye irritation and perhaps nausea. Tests are usually carried out in a clean workshop which is well ventilated and although the stated values exceed EH40 LTEL/ STEL recommendations (5ppm & 10ppm respectivelly), there is insufficient content/ volume of air released during a controlled test to cause harm.

I am afraid that I am always a little concerned when relatively high toxicity gases have to be used on a regular basis. At the end of the day one only needs to know a yes no presence indicator and I remain to be convinvced that the old fashioned lead acetate papers are not the best solution. They are very specific and sensitive Bob

I don't have experience of hydrogen sulphide monitors. I do have personal experience of another type of gas monitor. I have observed them calibrated, with good batteries, but not reacting to the gas correctly. I would therefore ALWAYS check that it is reacting to its specific gas before using it, since my life might depend on it.