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HR Noise Detector: quick reference – rev. 1.1
This Noise Detector causes the LED to light for every heart beat and/or transient 5Khz frequency
detected: in this way it is possible to determine whether there is electromagnetic noise, and identify
its source.
Keep the Noise Detector in your hand, with the coil to the front, and check around the TG
machine and, in general, into the room to find possible electromagnetic noises.
When you can see red LED repeatedly flashes, that means an electromagnetic noise has been
found. Faster is the LED blinking frequency nearest is the electromagnetic noise source.
The presence of electromagnetic noises is easily recognizable, respect standard Chest Belt
HR beats, because generally accompanied by fast and irregular blinking of the LED. While
Chest Belt beats are always regular in time (same blinking speed/same duty cycle).
3.4.
NOISE DETECTOR SATURATION
If an area is affected by high level of electromagnetic noise the Noise Detector may become
completely saturated. This phenomenon, depending on its intensity, may cause the device
impossible to receive any signal (LED always OFF), even if you wear a Chest Belt in front of it.
In this case it's really important to have a well working and tested Chest Belt to test the
Noise Detector, to avoid any doubts: if no signal is received by the Chest Belt as well, the Noise
Detector is saturated. To prove it you can move into another room/ area to check when HR beats
are detected again.
3.5.
ADDITIONAL NOTES
•
HR Noise Detector is very sensible. You can find at all the 5Khz spurious transient or
periodic noise pulses. If you keep it nearby an ARM display, for example, LED will flash
fast because display's LEDs and uP create electromagnetic noise. That's why HR receiver, on
our cardio machine, is always housed in a fixed and pre-tested position, far enough from
ARM display or the other source of noise produced by our machines (mains power cables,
AT/ALE driver, WTV/ Visio electronic boards...)
•
You can use the Noise Detector to check if distance from machine to machine is enough to
avoid cross talk phenomenon: when a user, wearing the Chest Belt, is training on one
machine, you can check at which distance the Noise Detector can still display beats. This to
prove at customer to respect the minimum machines required distance to avoid cross talking
issues.
Noise Detector, because its sensibility, can show beats even if you are far than 1mt
from the user wearing the Chest Belt. Cardio receivers installed on machines instead have
Page 3.5
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