Smokelyser to the rescue

This is a blip of my trusty Smokelyser which I use as part of my smoking cessation service.
One of our clients, who insisted they had given up smoking completely, kept on getting readings of 9 and over which normally would indicate that they had been smoking. They were very insistent that they hadn't and I believed them.
This client came into the pharmacy after work and we both wondered if the high readings were due to a ventilation problem at their place of work. To cut a long story short it turned out that the Health and Safety Executive were called in and had monitored the CO levels where they work and that the levels of CO were too high. Ventilation was improved and now we get the readings we expect. Smokelyser to the rescue :-)