BS EN ISO 7494-1:2018 pdf free

BS EN ISO 7494-1:2018 pdf free.Dentistry – Stationary dental units and dental patient chairs
If the armrest is designed to be moveable, adjust it to the position for use with a seated patient receiving dental treatment.
At the most critical location on the armrest, apply a force of 670 N vertically downwards for 1 min and subsequently apply a force of 440 N horizontally, in the inward and outward directions for 1 min in each direction.
Subject the test piece to a mass distributed in accordance with Table 1, plus the additional mass of items mounted on the dental patient chair as specified by the manufacturer as maximum lifting capability.
Activate the test piece for three uninterrupted up-and-down movements. Then operate the test piece intermittently three times using the control switch, performing three further complete up-and-down movements and position the seat of the test piece in a middle position.
Measure the height of the seat. Leave the test piece under load in the same position for 1 h. Then measure the height of the seat again and calculate the distance by which it has sunk.
A test fixture is required which has a vertical post that can be securely attached to the seat of the dental patient chair and a rigid arm extending horizontally from the vertical post capable of supporting a 400 N downward load applied 100 cm±1 cm from the vertical post. The vertical post shall be sufficiently long to allow the horizontal arm to be positioned at 45° increments in the horizontal plane, starting along the longitudinal axis of the dental patient chair under the conditions specified below. See Figure 1.
Install the dental patient chair according to the manufacturer’s instructions. Attach the test fixture to the seat of the dental patient chair where the patient sits when the backrest is in the fully upright position.
The test shall be performed at each 45° increment of the horizontal arm position with an unloaded (i.e. no patient load) dental patient chair positioned in the most adverse (i.e. unstable) position. Any movable parts, such as support arms, shall be loaded with their maximum load and adjusted to the most adverse position. Apply a load of 400 N vertically downward to the horizontal post of the test fixture at 1 m from the vertical post.BS EN ISO 7494-1 pdf download.