True Fitness Z9 Series Owner's Manual page 100

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chest strap, transmitter: use to detect heart rate, then transmit
using a 5 kHz radio signal to a receiver in fitness equipment (or
wristwatch). Originally invented by the Finnish company Polar in
the early 1980s, this technology is now widely available from other
sources.
CHR (contact heart rate) pads: stainless steel handgrips used to
detect ECG signals. Typically the two top pads are "hot" or positive,
while the two bottom pads are common. These pads are roughly
equivalent to lead I and lead III in a standard 12-lead ECG system.
constant power: a type of workload control system, most commonly
found on self-generating exercise bikes. Since power = torque x rpm,
a constant power system lowers torque when pedal rpm increases,
and increases torque when rpms decrease.
constant torque: a type of workload control system, most commonly
found on ellipticals and low-end plug-in exercise bikes. Unlike con-
stant power, torque does not change when pedal rpm does.
contact heart rate (CHR): a system to acquire ECG data from hand-
grips, eliminating the need for a chest strap. A better name would be
hand touch heart rate. CHR is less accurate than chest strap moni-
toring, and doesn't work well during high-intensity or strong-motion
exercise, such as running or upper-body exercise. Newer digital
CHR systems, are greatly improved in these areas.
CSAFE: Communications Specification for Fitness Equipment.
This poorly-acronymed spec was created by a consortium of fit-
ness equipment manufacturers back in early 1997. It is intended
to be a general-purpose data communication protocol on top of
RS232. Later additions to the spec included a small voltage supply
to power an external controller, and commands to control volume
and channel in entertainment systems. The original consortium
was, in alphabetical order: Cardio Theater, Fitlinxx, On Base, Precor,
Z 8 a n d Z 9 S e r i e s T r e a d m i l l O w n e r ' s G u i d e
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