LFY-711 Respiratory Resistance Tester

Main purpose/Use 
LFY-711 is used to measure the inhalation resistance and exhalation resistance of respiratory protective equipment and masks under specified conditions. It is applicable to national labor protection equipment inspection institutions and mask manufacturers for conducting relevant tests and inspections on ordinary masks, dust-proof masks, medical masks, and anti-haze masks products. 
Technical indicators 
1. The instrument is composed of an air source with adjustable flow rate, a standard human head model, two sets of pipelines for inhalation and exhalation, and a respiratory resistance measurement system, etc. 
2. The flow sensor has high sensitivity and a very low starting flow rate. 
3. The flow sensor chip adopts a thermal mass flowmeter, which eliminates the need for temperature and pressure compensation, ensuring the high accuracy of the sensor's measurement. The flow measurement range is from 0 L/min to 100 L/min, with an accuracy of ±2%. 
4. Multiple sensors are integrated onto a single flow sensor chip, significantly increasing the measurement range of the sensor. 
5. The zero point stability of the flow sensor is high. It has high stability across the entire range, high accuracy and excellent repeatability across the entire range. It also features low power consumption, low loss and fast response speed. 
6. The data recorder uses a 128×64 pixel graphic dot matrix liquid crystal display with a fully Chinese interface, making the operation very convenient. 
7. The data recorder has 4M of internal memory for storing measurement values. 
8. The micro-pressure sensor adopts two-wire communication, featuring high accuracy and good stability. It is designed with explosion-proof features, ensuring safe and reliable operation. 
9. The range and zero point of the micro-pressure sensor can be adjusted continuously externally. The damping can also be adjusted. There is no mechanical movable part, resulting in less maintenance workload. The range of the micro-pressure sensor is -1000Pa to 1000Pa, with an accuracy of 1Pa. 
10. The entire instrument is equipped with special gas path conversion components, ensuring that the two sets of pipeline systems for exhalation and inhalation can be switched smoothly and quickly. 
11. The suction pump has a suction capacity ranging from 40L/min to 100L/min. 
12. The ventilation volume is maintained at (85 ± 1) L/min. 
13. Power Supply: AC 220V, 50Hz 
14. Comply with the latest national standards requirements and be compatible with both labor protection masks and daily protection masks standards. 
Applicable Standards 
GB 2626-2019 Respiratory Protective Equipment - Self-Contained Filtering Respirator for Particulate Matter 6.5 6.6 
GB/T 32610-2016 Technical Specification for Daily Protective Masks 
GB 2890-2022 Respiratory Protection Self-Contained Filtering Respirator 6.9 
GB 19803-2023 Medical Protective Masks 
GB/T 16556-2025  Respiratory Protection - Self-contained Open-Circuit Air Breathing Apparatus