These digital devices deflate at about 4 mm Hg per second, making them sometimes seem slower to use than auscultatory aneroid devices, but they are more accurate.
Elevation was determined using an aneroid altimeter.
We calibrated the blood pressure measurement system prior to use each day with an aneroid sphygmomanometer.
He used a standard-sized, calibrated aneroid sphygmomanometer blood pressure cuff to measure pressure in the left arm.
The aneroid sphygmomanometers were inspected and calibrated by the Biomedical Engineering Department of the University of Michigan Health Systems.
He said that because Welch Allyn makes aneroid and digital blood-pressure devices in addition to those containing mercury, he had no further comment.
On July 17, 1929, he flew the first instrumented payload, consisting of an aneroid barometer, a thermometer, and a camera.
The mercury sphygmomanometer is a reliable device, but all too often its continuing efficiency has been taken for granted, whereas the aneroid manometer, which is not generally as accurate, is often assumed to be as reliable.
Thirdly, although aneroid sphygmomanometers are more popular than mercury instruments, they require regular calibration and checks for common defects such as non-zeroed gauges, cracked face plates, or defective rubber tubing.
These devices include mercury column monitors, which are being phased out of use, and aneroid monitors.