May I ask, [Environmental humidity: 5%～85%], what does the [5%～85%] here refer to?

一沙一世

May I ask, [Environmental humidity: 5%～85%], what does the [5%～85%] here refer to? [Copy link]

 

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Bluetooth parameters:

1. Working voltage (MAX): 1.8~3.6V. The module cannot work when the voltage is lower than 1.8V.

2. Total average power consumption of the module: less than 20uA

3. Working temperature: -20℃～60℃

4. Ambient humidity: 5%～85%

May I ask, [Environmental humidity: 5%～85%], what does the [5%～85%] here refer to?

maychang

"[Environmental humidity: 5% to 85%], what does this [5% to 85%] refer to? ]

It is relative to the saturated vapor pressure at that temperature.

一沙一世

maychang posted on 2022-8-8 10:07 "[Environmental humidity: 5%～85%], what is the [5%～85%] relative to? ' It is relative to the saturation at that temperature...

Thank you very much. What pressure is greater than what pressure?

maychang

At a certain temperature, there is a limit to the amount of water vapor that can be contained in the air. For example, at a temperature of 40 degrees Celsius, the partial pressure of water vapor in the air is at most 55.3 mmHg (millimeters of mercury), and the total gas pressure is 760 mmHg. At this point, we say that the relative humidity is 100%. Adding more water vapor will only cause the water vapor to condense (the "white smoke" we see when water boils is the water vapor condensing into mist). If the actual water vapor partial pressure is 27.65 mmHg at 40 degrees Celsius, the relative humidity is 50%. If the actual water vapor partial pressure is 11.06 mmHg at 40 degrees Celsius, the relative humidity is 20%.

maychang

Therefore, relative humidity is relative to the saturated vapor pressure of water vapor at that temperature.

maychang

Yishayishi published on 2022-8-8 10:17 Thank you very much. What pressure is greater than what pressure

"What pressure is greater than what pressure?"

It is the actual pressure of water vapor compared to the saturation pressure at that temperature.

一沙一世

maychang posted on 2022-8-8 10:30 "What is the pressure ratio of what?" It is the actual pressure of water vapor compared to the saturation pressure at that temperature.

Thank you very much, sir.

maychang

Yishayishi published on 2022-8-8 10:17 Thank you very much. What pressure is greater than what pressure

For example: a bottle can hold up to 200ml of water, and if you add more water to the bottle, the wine will overflow. Now the bottle is filled with 100ml of water, so we say that the "fullness" of the water is 50%.

But if we pour this water into a bottle that can hold a maximum of 400 ml of water (equivalent to an increase in ambient temperature), we say that the "fullness" of the water at this time is 25%.

chunyang

Contents of high school physics courses...

maychang

chunyang posted on 2022-8-8 11:23 The content of high school physics courses...

It's a pity that current high school physics textbooks no longer talk about changes in physical state, saturated vapor pressure, relative humidity...

chunyang

maychang posted on 2022-8-8 15:11 It is a pity that the current high school physics textbooks do not teach about changes in physical state, saturated vapor pressure, relative humidity...

Really? The college entrance exam is so difficult now, and the textbooks have been cut?! I remember that the relevant content was taught in the second year of high school, and there were calculation questions about relative humidity and absolute humidity in the exam, and they were not difficult...

maychang

chunyang posted on 2022-8-8 15:19 Really? The college entrance examination is so complicated now, and the textbooks have been cut? ! I remember that the relevant content was taught in the second year of high school, and the exams all had questions about relative humidity and absolute humidity...

Nowadays, high school physics textbooks do not even mention surface tension. Therefore, it is not easy to explain how to judge the soldering work of circuit boards.

Without mentioning the saturated vapor pressure, it is impossible to explain why water boils at 100 degrees Celsius.