There seem to have been a more questions about humidity and humidifiers lately, so here's a few quick tips that are independent of the humidifier system you use.
Relative humidity is "relative" to the temperature. It's a measure of how saturated the air is. Warm air hold more moisture than cold air. So, increasing or decreasing the temperature in a humidor will change the RH reading without actually changing the amount of moisture in your humidor (coolerdor, tuperdor, panty drawer, whatever).
One consequence of this is that that an RH reading, without a simultaneous temperature reading, is useless. It's like telling someone how much water you have by saying that your bucket is 2/3 full, without telling them how big the bucket is. 5 gallons or 1 gallon? Frank, supposedly, has a big bucket, but I've never seen it, that's just the innuendo on the street.
One corollary to this is to say goodbye to analog RH hydrometers and good riddance. Without a temperature reading, they're as useful as a football bat. I got a nice Elie Bleu humidor as a gift one time, and it had an analog hydrometer in it. I couldn't believe it. I threw it away (the hydrometer, not the humidor). Cheap bastards!
People on the forum often talk about RH without talking about temperature. I think it's because most people are just assuming 70F. (I'm not going to talk about why Americans still use Fahrenheit and the imperial system of measurements. cause, well, 'Merica!)
But small changes in temperature make a big difference in the RH reading. The official fiction is 70Rh at 70F. But I think most people on the forum prefer the RH a little lower. I like my cigars in the 65-70 range at 70F, with 68Rh being about ideal, but tastes vary. You don't need to be anal retentive about it. Don't get me wrong, I'm not one to judge a man for retaining whatever he wants in his anus (none of my business), but for humidor purposes, think more about a range of humidity rather than an exact amount. You'll work less and enjoy more. I'm mostly happy with anything between 62 and 72 RH at 70 degrees. With my ideal of 68RH, dropping the temperature from 70 to 67 raises the RH to 75, but it doesn't change the amount of moisture, just the RH. If you didn't know the temperature, and just saw 75RH, you might think it's too high, but it's not. It's perfect.
The simplest and easiest to use online RH converter that I am aware of is at this link.
http://bmcnoldy.rsmas.miami.edu/Humidity.html
Click the "Fahrenheit" button because you're backwards and antiquated like the rest of us. Then enter the temperature and RH from your digital hydrometer, and calculate the dew point. For these purposes, the dew point represents the amount of moisture in your box, so leave that alone. You can then change the temperature and recalculate the RH to see what the RH would be a different temperatures given that amount of moisture. It's easier than I make it sound. Unless you maintain your house at exactly 70F year round, you should be using something like this calculator to know exactly how moist your sticks really are.
If you have any questions about any of this, don't hesitate to PM clintCigar. He's the real resident expert around here on RH and humidifying systems.