ISSUE: A leak in the tubing that connects the respiration transducer to the polygraph instrument.
Option #1– If the leak is close to the instrument your fastest and easiest fix is to simply cut the hose just past the leaking point on the pneumo side. After you have done this remove the end that connects to your instrument from the cut portion of hose and connect it to the newly cut end that leads directly to your pneumo. For this to work the leak will have to be close enough that after you cut the hose it is still long enough to reach your examinee.
Option #2 – If the leak is close to the pneumo your fastest and easiest fix is to simply cut the hose just past the leaking point on the instrument side. After you have done this remove the hose end that connects to your pneumo and connect the newly cut end that leads directly to your instrument directly to your pneumo. For this to work the leak will have to be close enough that after you cut the hose it is still long enough to reach your examinee.
Option #3 – If the leak is not close to either end of the hose you will have patch the leak temporarily until your hose can be replaced. The ideal way to fix this problem is to have a spare barbed coupler, this will allow you to cut the tubing at the leaking point and reconnect both ends. It will also guarantee a good non leaking fix (you can usually find something close enough to the correct size in most hardware stores, check the small engines section, in particular look where they keep the gas line parts). Other patch methods include: Good ole’ duct tape, electrical tape (matches the hose color nicely), latex caulking (fairly fast drying), silicon based caulking (these take a long time to dry), and heat shrink.
ISSUE: A visible hole in the rubber bellow of the pneumatic transducer.
Option #1– Repair the hole using rubber glue/cement. Depending on the size of the hole you may need to use a patch.
Option #2 – Repair the hole using Latex caulking. This solution should dry quickly and remedy the leak temporarily.
Option #3 – Repair the hole using a Silicon based caulking. This option will take longer to dry but will provide a more flexible solution that will last longer than the Latex caulking.
ISSUE: A leak in the respiration transducer due to a dried out/cracked rubber bellow. This issue is more difficult to repair and can be prevented by properly inspecting the condition of the pneumatic transducers regularly. Very dry/cracked pneumos will likely be leaking from multiple points on the bellow.
Option #1 – Repair the cracks in the bellow by applying a coat of rubber glue/cement. This will hopefully temporarily seal the cracks and stop the leak.
ISSUE: A disconnected shock cord inside the respiration transducer. The shock cord is attached to both pneumo ends using two pins which are pressure fitted into the ends through a metal sleeve which is attached to both ends of the shock cord. This provides a sturdy strong connection and we rarely see this issue. Signs of this problem are an elongated pneumo which does not compress back to its normal length when stretched.
Option #1 – You will need to start by removing the bellows potion of the pneumo from the pneumo ends and you can do this by hand without too much difficulty. Just pull gently and twist and the bellow should come off. If the shock cord has been separated from one of the metal ends which is pressure fitted and held in place by the metal pin you will need to re insert the shock cord and pinch the metal sleeve. First use a pair of needle nose pliers to open up the metal sleeve so that it is easy to re insert the shock cord. Next insert the shock cord and pinch the metal sleeve with the pliers firmly in at least two locations. Pay attention to the way the metal sleeve closes and be sure to pinch it so that the sleeve is closing in on itself. You can complete the field repair by putting some silicone or latex caulking on the pneumo ends and sliding the rubber bellows back into place.