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5. CARRYING OUT A MEASUREMENT
5.1. Before the measurement
• Avoid eating, smoking as well as all forms of exertion directly before measurement. All these factors
influence the measurement result. Try to find time to relax by sitting in an armchair in a quiet
atmosphere for about 5 minutes before measurement.
• Remove any garment that fits closely to your upper arm.
• Always measure on the same arm (normally left).
• Take measurements regularly at the same time of day, since blood-pressure changes during the course
of the day.
5.2. Common sources of error
Note: Comparable blood-pressure measurements always require the same conditions! These are normally
always quiet conditions.
• All efforts by the patient to support their arm can increase blood-pressure. Make sure you are in a
comfortable, relaxed position and do not activate any of the muscles in the measurement arm during
measurement. Use a cushion for support if necessary.
• If the arm artery lies considerably lower or higher than the heart, an false reading will be obtained.
Each 15cm difference in height results in a measurement error of 10mmHg!
• Cuffs that are too narrow or too short result in false measurement values. Selecting the correct cuff is of
great importance. The correct cuff size is dependent upon the circumference of the arm (measured in the
centre). The permissible range is printed on the cuff. If this is not suitable for your use, please contact
your dealer for the correct size. The permissible range for a Medium cuff is 22-32cm while the permis-
sible range for a Large cuff is 32-42 cm. Note: Only use clinically approved Microlife Cuffs!
• A loose cuff causes false measurement values.
5.3. Fitting the cuff
a) Push the cuff over the left upper arm so that the tube points in the
direction of the lower arm.
b) Place the cuff on the arm as illustrated. Make certain that the lower
edge of the cuff lies approximately 2 to 3 cm above the elbow and
that the rubber tube leaves the cuff on the inner side of the arm.
c) Tighten the free end of the cuff and close the cuff by affixing the
Velcro.
d) The cuff should be snug on your upper arm so that you can fit 2
fingers between the cuff and your upper arm. Any piece of clothing
which restricts the arm (e.g. a pullover) must be taken off.
e) Secure the cuff with the Velcro closer in such a way that it lies
comfortably and is not too tight. Lay your arm on a table (palm
upwards) so that the cuff is at the same height as the heart. Make
sure that the tube is not kinked.
Comment: If it is not possible to fit the cuff to your left arm, it can also
be placed on the right. However, all measurements should be made using
the same arm.
2–3 cm
tube
