As many countries including the United States have started to ease COVID-19 restrictions the World Health Organization and the Center for Disease Control and Prevention are directing the public to wear masks when in public space. Wearing a mask helps to prevent the transmission among individuals who may be a carrier or ill with COIVD-19. We want to ensure you take the correct steps when wearing your mask. Listed below are the steps you can take to ensure you are properly wearing your mask.
How to wear a mask:
Step 1) Perform hand hygiene before putting on your mask.
Step 2) Hold the KN95 in your palm with the nosepiece at the fingertips and allow for the head straps to hang freely below your hand.
Step 3) While holding the KN95 in place, pull the left strap over your ear and do the same with the right strap
Step 4) Using both hands, mold the nosepiece to the shape of your nose by pushing downward and outward. While moving your fingertips down both sides of the nosepiece.
Step 5) Perform hand hygiene after putting on mask.
An encoder is an electrical mechanical device that converts linear or rotary displacement into digital or pulse signals. The most popular type of encoder is the optical encoder. This consists of a rotating disk, a light source, and a photo detector (light sensor). The disk, which is mounted on the rotating shaft, has patterns of opaque and transparent sectors coded into the disk (see Figure 1). As the disk rotates, these patterns interrupt the light emitted onto the photo detector, generating a digital or pulse signal output.
An incremental encoder generates a pulse for each incremental step in it's rotation. Although the incremental encoder does not output absolute position, it can provide high resolution at an acceptable price. For example, an incremental encoder with a single code track, referred to as a tachometer encoder, generates a pulse signal whose frequency indicates the velocity of displacement. However, the output of the single-channel encoder does not indicate direction. To determine direction, a two-channel, or quadrature, encoder uses two detectors and two code tracks.
The most common type of incremental encoder uses two output channels (A and B) to sense position. Using two code tracks with sectors positioned 90° out of phase, the two output channels of the quadrature encoder indicate both position and direction of rotation. If A leads B, for example, the disk is rotating in a clockwise direction. If B leads A, then the disk is rotating in a counter-clockwise direction. Therefore, by monitoring both the number of pulses and the relative phase of signals A and B, you can track both the position and direction of rotation.
In addition, some quadrature detectors include a third output channel, called a zero or reference signal, which supplies a single pulse per revolution. This single pulse can be used for precise determination of a reference position
As far as how well they protect against COVID-19 and filter out particles, a KN95 and N95 are the same. But there are a few differences on other fronts.
·KN95 meet Chinese standards for masks, while N95 masks meet US standards.
·Every country has its own standard. Ex. KF94 is the Korean code, FFP2 is the EU and UK code.
·Both KN95 and N95 masks are rated to capture 95% of tiny particles (0.3 micron particles).
·Both KN95 and N95 masks fit tightly around your nose and mouth.
·KN95 mask manufacturers are required to run fit tests on humans with ≤ 8% leakage, while N95 masks are not.
·N95 masks have slightly higher restrictions for pressure drop while inhaling and exhaling (read: better breathability).
With such similar sounding names, it can be confusing to understand the difference between N95 and KN95 masks. What are KN95 masks, and are they the same as N95 masks? This handy chart explains the differences between N95 and KN95 masks (and all characteristics that are the same).
In short, N95 masks are the US standards for respirator masks; KN95 masks are the Chinese standards for masks. These are the requirements that the US National Institute for Occupational Safety and Health requires manufacturers to meet in order to label their masks as N95s. Despite the long list of differences, the two masks are equivalent or nearly equivalent on the features that most people care about.
N95 vs. KN95 Comparison Chart