The shock is from the build up of static electricity.
10 20 humidity static electricity vinyl envelope.
During the winter the humidity inside a heated space can be very low.
This increases the condutivity of most things enough that static charges are drained off.
Unfortunately 60 relative humidity is extremely uncomfortable can cause equipment problems and introduce contaminants into your system.
Table 2 1 typical measured static charges in volts relative humidity item low 10 20 high 65 90 walking across carpet 35 000v 1 500v walking over vinyl floor 12 000v 250v worker at bench 6 000v 100v vinyl envelopes for work instruct.
Nfpa 77 1 batterymarch park quincy ma 02169 situation electrostatic voltages kv rh 10 20 rh 65 90 walking across a carpet 35 1 5 walking across a vinyl floor 12 0 25 working at a bench 6 0 1 vinyl envelopes for work instructions 7 0 6 poly bag picked up from bench 20 1 2.
Vinyl envelopes for work instructions 7 000 v 600 v.
Increasing humidity to 60 limits static build up because surface moisture on materials makes a good conductor.
Walking across a carpet.
Worker at bench 6 000 v 100 v.
Means of static generation rh 10 20 rh 65 90.
10 to 20 relative humidity 65 to 90 relative humidity walking on carpet 35 000 1 500 walking on vinyl floor 12 000 250 worker at bench 6 000 100 vinyl work instruction envelopes 7 000 600 common poly bag picked up from bench 20 000 1 200 polyurethane foam padded chair.
Walking on a vinyl tile floor.
Humidity and esd electrostatic voltages 10 20 rh 65 90 rh walking across carpet 35 000 1 500 walking over vinyl floor 12 000 250 worker at bench 6 000 100 vinyl envelopes for work instructions 7 000 600 common poly bag picked up from bench 20 000 1 200 common chair padded with polyurethane foam 18 000 1 500.
Table 10 1 typical measured electrostatic voltages voltage levels relative humidity means of static generation low 10 20 high 65 90 walking across carpet 35 000 1 500 walking over vinyl floor 12 000 250 worker at bench 6 000 100 vinyl envelopes for work 7 000 600 instructions common poly bag picked up from 20 000 1 200 bench work chair padded with urethane 18 000 1 500 foam 10 16.
Table 6 3 electrostatic voltage at workstations static voltage means of static generation relative humidity 10 20 relative humidity 65 90 walking across carpet 35 000 1 500 walking over vinyl floor 12 000 250 worker at bench 6 000 100 vinyl envelopes for work instructions 7 000 600 common polly bag picked up from bench 20 000 1 200 work chair padded with urethane foam 18 000 1 500.
During the summer the indoor humidity tends to be high.
Means of static generation.
Two levels of relative humidity rh ref.
Static is rarely a problem.
Walking across a carpet 35 000 v 1 500 v.
Vinyl envelopes for work instructions.