Heart Rate sensor

The Heart Rate sensor ML87s monitors a person’s heart rate. The sensor measurement range is between 0 and 250 beats per minute (bpm). The Heart Rate sensor consists of a transmitter belt and a receiver. The transmitter belt has to be worn just below the chest and held in a place by an elastic strap delivered with the sensor. The transmitter detects electrical signals at the surface of the skin by two electrodes embedded in the chest belt and transmits the information to the receiver via a low frequency electromagnetic field. The receiver receives the signals and determines the heart rate in beats per minute. The reception range of the receiver is 90 cm.
The transmitter switches off automatically as soon as there is no skin contact between electrodes and the belt. Store the belt dry. The battery in the belt has lifetime of about 2500 transmit hours. Then the belt has to be replaced.

Suggested experiments
• Compare the heart rate of different individuals.
• Check the person’s heart rate before, during and after a short period of vigorous activity.
• Monitor the recovery rate: that is how fast a person’s heart rate returns to normal after exercises.
• Check for baroreceptor reflex: that is, changes in heart rate for a person when reclined, sitting, and standing caused by the need for the heart pump blood to different levels.
• Check a person’s heart rate before and after caffeine consumption.
• Check a person’s heart rate before and after eating.
• Check your own heart rate at different times of the day.
• Monitor a person’s heart rate as they hold their breath.

The Heart Rate sensor ML87s is a digital sensor (on-sensor digital conversion), which gives calibrated values of the measured quantity. This sensor can only be connected to the CMA MoLab interface and not to other CMA interfaces such as VinciLab, CoachLab II+ or EuroLab.

Technical specifications of the sensor are described in its User's guide.