Can an iPhone be used as a scale? [Reporter's actual measurement: the same tomato has different weights three times]
Wuhan Evening News (trainee reporter Fan Youhan) Can a mobile phone also be used as a scale?
Recently, some netizens "revealed the secret": Apple's mobile phone has a weighing function, it doesn't matter if you don't bring a scale to the vegetable market, you can weigh items by placing them on the screen of the mobile phone, which has caused heated discussions.
On the 9th, the reporter visited the vegetable market to measure this function and found that the weighing data of the mobile phone had a large error compared with the weighing data of the electronic scale of the vegetable market.
In addition, the same tomato is weighed 3 times with the mobile phone, and the weight displayed is different for the 3 times.
In the online post, netizens used their mobile phones to weigh an orange, a banana, and a mango successively, and the results were displayed to the nearest two decimal places, which were 29.82 grams, 55.25 grams, and 394.14 grams, respectively.
Then, she demonstrated how to turn on the weighing function of the mobile phone: first open "Settings", find "Accessibility", then click "Touch" to turn on "3D Touch", and finally search for "Touchscale" through the browser, you can use The phone is weighed.
At about 14:00 on October 9, the reporter came to the Yilihe Fresh Market in Jiang'an District and found a fair weighing platform at the elevator on the second floor.
The reporter put the purchased sweet potatoes, tomatoes and zucchini on the weighing platform in turn, showing 395 grams of sweet potatoes, 195 grams of tomatoes, and 390 grams of zucchini.
Then, the reporter went to Houhu Fresh Vegetable Market in Jiang'an District, and used the market's fair weighing platform to weigh the above items again, and got the same result.
Subsequently, the reporter turned on the weighing function of the mobile phone. The blue area of the weighing page showed that the initial gram of the item was "0.00g"; the white area was the item placement area, marked "Place the item in this area, such as an apple".
The reporter weighed the tomatoes and other items on the screen of the mobile phone as required, and found that the weight displayed on the mobile phone was inconsistent with the weight displayed on the weighing platform.
Tomatoes and zucchini were "heavier" by more than 20 grams, showing 218.87 grams and 416.43 grams, and sweet potatoes were "heavier" by more than 40 grams, showing 438.72 grams.
To the reporter's surprise, the reporter weighed the same item on the screen of the mobile phone three times, and the result of each weighing was different.
For example, the weight of the tomato is shown as 218.87 grams, 243.18 grams, 245.12 grams.
What is the principle of mobile phone weighing?
Is it right?
On the 9th, the reporter interviewed Zhao Xiaogang, a teacher of the Department of Computer Science of Wuhan University.
He introduced that the Apple mobile phone weighs using the pressure-sensitive touch screen function.
"The core is to sense the pressure exerted by the outside world and convert it according to a certain formula to obtain the weight of the object. In addition to Apple mobile phones, other mobile phones with this function can also be weighed."
Zhao Xiaogang said that each time an irregular object is placed on the mobile phone screen, the contact point with the screen may be different, and the pressure applied to the mobile phone is also different, which will lead to errors.
Putting the object on the screen and weighing it several times, taking the average weight, may reduce the error.
"It is still recommended to take the electronic scale as the standard, and Apple does not recommend that you weigh in this way, because you are worried that the pressure sensor will be damaged by overweight items."