Vibration Meter, seismograph vs Video tachometer

Vibration meter is an app called seismograph or seismometer, which measures the strength of vibration, quakes, earthquakes, vibrations of the human body or any other objects around you. Our app allows for detecting and recording of seismic waves generated by earthquakes, volcanic eruptions, avalanches and other sources of vibration and shocks. Accelerometer in your mobile phone is used for detection of vibrations and measurement analysis. Graph presents a record of the ground motion at a measuring point. Ground movement or an object is presented as a function of time in the three Cartesian axes, with the z axis perpendicular to the Earth's surface and the x- and y- axes parallel to the surface. Mercalli intensity scale is a seismic scale used for measuring the intensity of an earthquake. It measures the effects of an earthquake and it is distinct from the moment of magnitude. Richter Scale assigns a magnitude number to quantify the energy released by an earthquake. Peak Ground Acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake. In this app we use Instrumental Intensity Scale (developed by The United States Geological Survey) which maps peak ground acceleration and peak ground velocity on an intensity scale similar to the felt Mercalli Scale. These values are used to create shake maps by seismologists on around the world. Mercalli Intensity Scale distinguishes the following levels of vibration and impact damage: I. Instrumental - Not felt. Recorded by seismographs. II. Weak - Felt only on top floors of high buildings. III. Slight - Felt indoors, like a passing light truck. IV. Moderate - Windows, doors rattle. Like passing train. V. Rather Strong - Felt by all. Small objects upset. VI. Strong - Books off shelves. Trees shake. Damage. VII. Very Strong - Difficult to stand. Buildings damaged. VIII. Destructive - Significant damage. Trees broken. IX. Violent - General panic. Serious damage. Cracks. X. Intense - Most buildings destroyed. Rails bent. XI. Extreme - Rails bent greatly. Pipelines destroyed. XII. Catastrophic - Near total damage. This app allows you monitor and share the results of your measurements with other users. Measure and monitor all vibration and shocks using smartphone or tablet!

When the frame rate of a video matches the speed of a particular part, the effect is the same as using a strobe light. In the video, that part freezes. Since the frame rate of a video can be adjusted, this effect can be used to determine the rotational speed of a part. The smartphone must support slow-motion video recording (filming at a high frame rate). This is the case for all smartphones starting with iPhone 5S. The range is as follows: • 0.5—240 Hz (30—14400 RPM), for all phones from iPhone 6 onward • 0.5—120 Hz (30—7200 RPM), for iPhone 5S THE HERTZ (Hz) VALUE IS MORE ACCURATE THAN THE REVOLUTIONS PER MINUTE (RPM) VALUE, SINCE REVOLUTIONS PER MINUTE ARE CALCULATED FROM HERTZ AND ROUNDING IS DONE. To get a clear image, good lighting is important. The clarity of the image is controlled by the exposure of the video (exposure time and light sensitivity (ISO)). If the exposure time is reduced, the image will increase in clarity, but brightness will lower. To increase the brightness, you need to raise the camera's light sensitivity (ISO), but then the amount of noise increases. You also need to manually adjust the focus of the camera. The app can record video. The video format depends on the selected format in the app settings. If your iPhone supports 4K video format (3840x2160), then you can record 4K video at the frame rate supported by your iPhone. Text with important information is added to the frames of the recorded video: the selected frame rate, exposure duration, ISO, time stamp, time difference between the current and previous frames (Tcurr. − Tprev.), the sequence number of the frame in the recorded video. If you want any other information to be added, then let me know. You can choose to add only part of this information, and you can choose a different text color. You also have the option of not adding any information. You can change the information that is added and the color of the text while recording a video. At high frame rates, frames that do not have time to be processed may be discarded. This does not affect subsequent frames and can be controlled using the time difference between the current frame and the previous frame (Tcurr. − Tprev.). Dropping frames affects the video frame rate displayed in the "Photos" app. But the time interval between frames that were taken one after another and were not discarded will correspond to the selected frame rate. Frames may be dropped even when shooting slow motion video using the "Camera" app. You can check this by looking at the frame rate for slow motion video in the "Photos" app. Video containing the app's interface can be captured using the iOS "Screen Recording" function. The app can take a photo with the measurement result, date, and time written on the photo. The exposure time and ISO settings will be saved in the photo's metadata. To take a photo that shows the app interface, tap the "Pause" button and take a screenshot. It is possible to choose a video format that has the best quality, but has a significantly lower maximum frame rate. The difference between the formats is clearly visible only when using the digital zoom. Also, when using a format with better quality, the Rolling Shutter effect is stronger. Therefore, the best quality format can be used at speeds less than about 2000 rpm. You can turn on hints for easier observation of changes in rotation speed. Hints show how to change the frame rate (decrease or increase) depending on the direction of rotation of the mark. The hints are selected manually, but then you do not need to remember this information. The hints are relevant for frequencies close to the rotation frequency. If the direction of rotation of the impeller is known, hints can be selected in advance. The arrow showing the direction of rotation of the impeller must correspond to the "+" button. The video tachometer measures the rotational speed in exactly the same way a stroboscopic tachometer would.