Influence and definition of respirator respiratory resistance
Mask is a kind of sanitary product, which is generally worn on the mouth and nose to filter the air entering the mouth and nose, so as to block harmful gases, odors, droplets, viruses and other substances. It is made of gauze, paper and other materials. It has a certain filtering effect on the air entering the lungs. When respiratory infectious diseases are prevalent and working in dust and other polluted environments, Wearing a mask has a very good effect.
In the past two years of anti epidemic, we can clearly understand the importance of masks, and the main evaluation indicators of mask quality include filtration efficiency, respiratory resistance and adaptability. Due to limited space, we mainly talk about respiratory resistance in detail.
The respiratory resistance of mask refers to the increased resistance of mask to breathing after the mask is worn according to the specification, including inspiratory resistance and expiratory resistance. The purpose of measuring the airflow resistance is to ensure that the person wearing the mask can not lack oxygen due to excessive resistance under high working intensity. Measuring the airflow resistance requires a fixed flow of airflow through the mask, and then measure the pressure difference on both sides of the mask. On the premise of determining the flow, the pressure difference reflects the resistance. Therefore, the airflow resistance is often expressed by the pressure parameter value (PA) or the pressure parameter value (PA / cm2). Ventilate from outside to inside and measure inspiratory resistance; The expiratory resistance was measured by ventilation from the inside to the outside. Generally speaking, the better the protection and the higher the filtering performance of the mask, the greater the airflow resistance will be, and the set standard value will be too large. At the same time, the respiratory load will be increased due to the airflow resistance, which will affect the comfort of the mask wearer. It may be more difficult to tolerate basic diseases with cardiopulmonary insufficiency. According to China's industrial standards, for life protection masks, the inspiratory resistance shall not exceed 175 PA and the expiratory resistance shall not exceed 145 PA. Labor protection masks, with inspiratory resistance not exceeding 350 PA and expiratory resistance not exceeding 250 PA [17,18]. For disposable medical masks and medical surgical masks, the ventilation resistance on both sides shall not be greater than 49 PA / cm2 [19,20,21]. Medical protective mask. The standard is tested under the flow rate of 85 L / min, and the suction resistance of the mask does not exceed 343.2 PA (35 mmh2o) . During the period of New Coronavirus pneumonia, try to avoid breathing mask with excessive breathing and inhalation for elderly people, children or pulmonary insufficiency.
In addition, respiratory resistance is an important index to evaluate the comfort performance of mask. Wearing dust-proof mask will increase the wearer's respiratory resistance. The range of resistance increase will vary according to the individual's respiratory frequency, depth and lung ventilation. Excessive resistance can cause narrow respiratory tract, increased oxygen consumption and dyspnea, resulting in the decrease of the wearer's working ability. On the contrary, the smaller the resistance of the dust mask, the smoother the human body will feel when breathing with the mask.
For ordinary consumers, the most practical feeling about the respiratory resistance of masks is "stuffy or not". For children, this is the reason why they can't wear three-dimensional masks with better protective effect, because although the protective masks have high filtration efficiency, they also have large respiratory resistance, especially in summer.
Masks appear frequently in life. Therefore, choosing appropriate masks with good quality can be said to have many benefits. The sgj372f respiratory resistance tester produced by our company for respiratory resistance can be used to measure the inspiratory resistance and expiratory resistance of respirators and various respirator protective articles under specified conditions. It has been highly praised by major testing institutions, third-party testing institutions, research institutes and manufacturers.