what is the relationship between humidity and voltage?

  • what is the relationship between humidity and voltage?
  • which humidity sensor do you recommend using in arduino?
  • what is the relationship between humidity and voltage?
  • which humidity sensor do you recommend using in arduino?

As the question was posed, easy answer, no relationship.

what is the relationship between humidity and voltage?

If a particular sensor uses voltage to represent humidity, the data sheet for that sensor will specify the relationship (transfer function).

I use the DHT22. It is not a great sensor but it is adequate for what I want and it is cheap. I am sure that there are better sensors, but they will cost more.

This page may be of interest.

Or this one.

Consumer technology has advanced so much that even the cheapest sensors made for arduino users is more
than adequate for almost any application. The scenarios where a high degree of accuracy is required do not
generally involve the average person. They are either scientific, medical , or military, (agricultural is included
in the category scientific because farmers don't generally require mil-spec humidity readings.

If a particular sensor uses voltage to represent humidity, the data sheet for that sensor will specify the relationship (transfer function).

I use the DHT22. It is not a great sensor but it is adequate for what I want and it is cheap. I am sure that there are better sensors, but they will cost more.

That answer is about the safest general answer to your question that I can imagine.
I think it goes without saying that anyone with any electronics experience would already know that. Here on
the forum we have to assume the 'worst case " scenario, that being a newbie who doesn't even know Ohm' Law
and maybe knows the resistor color code but probably would draw a blank when asked what "TTL" means.

There are two (common) types of humidity sensors:

  1. outputs a voltage as a function of humidity. The relationship is defined by each manufacturer and can be different for different sensors.

  2. outputs are digital (usually serial). No voltage outputted.

I was going to say, depending on there the voltage was connected to your body, increasing voltage could make you sweat (a kind of humidity) :slight_smile:

There is a new DHT-like humidity sensor on the market now, the AHT-10. Modules are available. It's worth checking out, I haven't had the time.

Looks like an interesting device. I'm a sucker for a more accurate device although I realize it doesn't have any practical implication for me.

Since the output is digital (I2C) I would assume 0 out = 0% humidity and 100 out = 100% humidity.

The specification I round says the

● Input voltage range: 1.8V to 3.6V;
● The factory is calibrated and calibrated, and the product has the function of temperature compensation.
● It has the functions of I2C interface and alarm.

● strong anti-interference ability
● Ultra low power consumption;
● SMD packaging;
● The humidity accuracy is + 2% RH (typical value).
● The temperature accuracy is 0.3 C (typical value).

aarg:
There is a new DHT-like humidity sensor on the market now, the AHT-10. Modules are available. It's worth checking out, I haven't had the time.

Same manufacturer (Aosong) as the DHT series.