Re: Watches vs Monitors:

[Roger Rittenhouse-vmaxept <roger@vmaxept.com>]

Karen wrote the following 
> 
> 
> Roger- Could you enlighten us with a post on Ride Camp as to the exact watches that will
> give out the false readings on the monitors.  I know you understand "Analog", but It's Greek
> to me and many others.  You spoke to me at the Cal Expo event and demonstrated the
> effects those watches create, but I don't know what Brands  are what or how us riders can
> identify what to avoid.  K-Mart and other places we buy these $30 watches that we wreck
> or lose con't have staff that can explain enough to all of us.  Thank you for straightening this
> out for me and many others.  Karen Nelson
> 
> 
There does not appear to be any brand of regular time piece-- standard
electric watch that causes interference with the heart monitor rec. The
design of the electric watches that use a quartz crystal to trigger the
very small motor that drives the gears of the analog-- time piece
The electric pulse sent to the motor will emit a pulse EMF--electro
magnetic..  which is picked up by the heart monitor rec
This will only occur IF the two devices are very close - as on the same
wrist- next to each other.
 A windup analog watch will NOT cause interferance - since it has no
electric motor
I have seen many riders especially in CTR wearing both devices on the
same wrist. I first noted this in 91 when I was at a rider briefing and
I kept hearing this beeping from a monitor. The rider set the LOW HR
alarm to 48.
I took the watch off the riders arm and it quit. Back then most riders
used the standard electric analog watch to time the ride as the normal
time piece.
She put it back on and it started to beep and was reading 60.
Move to the other wrist and it quit.
 The newbie rider was Patti Pizzo and the Horse was SAM in the early
days   Kinda nice-   since I crewed for her at Panam.

Still happens today.
The riders figure it out... BUT the PR takers using the handheld monitor
- need to be told NOT to wear another watch-- unless its DIGITAL.

I have noted this occurs on the HRM's that use POLAR, CARDIOSPORT and
SENSOR DYNAMICS Rec monitors.
Our latest module supplier - Acumen - the rec does not pick up the pulse
from the electric analog watch. These models have more filtering and
will only function with the transmitter from that company.. both a good
and bad design- but it resolved some interference problems

I think that should clear up that issue
Roger R


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Ridecamp is a service of Endurance Net, http://www.endurance.net.    
Information, Policy, Disclaimer: http://www.endurance.net/RideCamp   
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=