Accuracy with
without mercury


Pressure Cycle Test – Accoson greenlight 300 sphygmomanometer


To subject the greenlight 300 to a minimum of 10,000 pressure cycles, each one representing a full scale inflation and deflation, in the manner of a manual inflation and deflation of the device as in normal use.


The greenlight 300 was connected to a standard reference manometer with a pressure cycle function. It was then subjected to a total of 10,500 pressure cycles over a period of ten days. Each pressure cycle was a rise then a fall in pressure starting at 0 mmHg and ending at 300 mmHg as follows:

0 –100 / 100 – 90 / 90 – 180 / 180 – 170 / 170 – 250 / 250 – 235 / 235 – 275 /
275 – 260 / 260 – 300

The time dwell at each pressure was the minimum in order to allow the reference manometer to stabilise at the set pressure.

At the start of each session the calibration of the greenlight 300 was checked in steps of 20mmHg from 0 to 300mmHg. The automatic pressure cycle was then run, and the number of cycles noted. The calibration was then checked again both before and after the greenlight was turned off which activates the automatic pressure zero. All three sets of readings were noted, together with the temperature and the number of pressure cycles applied.

The results were expressed as VERNIER units, each one being 0.4 mmHg.

Note: The vernier display is made up of 5 LED’s for each 1 LED in the main display. Each vernier represents 0.4mmHg, and each main scale LED represents 2mmHg. To interpret the calibration results it is necessary to multiply the figure shown in the table by 0.4mmHg in order to arrive at the actual error in mmHg.


A total of 640 pressure readings were recorded

238 (37%) indicated an error of 0 mmHg
298 (47%) indicated an error of 0.4 mmHg
104 (16%) indicated an error of 0.8 mmHg


The maximum indicated error both during the test and after 10,000 pressure cycles was +/- 0.8 mmHg, confirming compliance with both European and American standards which specify a maximum error of +/- 3 mmHg.


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