Notifications
Clear all

Tutorials Is your Humidity sensor lying to you? Poor mans way to calibrate your sensor.

2 Posts
2 Users
8 Likes
1,068 Views
Sevans
(@sevans1965)
Posts: 1166
Linalool Respected User VIP
Patreon Bling
Active Grow Diary Bling
10k Post Likes
5 Complete Grow Diaries
Discord Member
Member for 1 Year
500 Posts Bling
Cali Cowboy Grow Off Bling
Topic starter
 

If humidity data is important to you, read on. 

Lots of talk recently about Humidity sensors. Obviously we are concerned about humidity, and some folks will assume their data is accurate ! 

Here are a few facts, some folks may not be aware of—

  • Most Humidity Sensors in our price point have an accuracy of +/- 3.0% RH, or worse!
  • Your new sensor may, or may not be calibrated! Or the calibration is off from the factory (unless I receive a caliper or other measuring device with a “calibration” certificate, consider it NOT calibrated! (Anyone that has purchased calibrated measuring devices, there is usually an extra charge for the calibration)
  • Once calibrated, it is not calibrated for life (it will drift)! It “should” be calibrated at some interval. If you test or calibrate annually, you’ll likely catch a faulty or dying sensor before you have trouble with your grow.

Here is a method for testing, same method can be used to calibrate if your device has a calibration option (AC Infinity, and PulsOne, to name a few can be calibrated by the owner). But you gotta make sure your temp measurement is accurate! Refer to the salt table below to reference salt type and temp for the correlating RH reading. 

  1. Place a handful of salt in the bottom of a jar (quart or liter size is fine).
  2. Add a little water to the jar so that the salt is wet. Note: The goal is to end up with wet salt, not to totally dissolve the salt.
  3. Place the Relative Humidity Sensor in the jar. Note: Do not get the salt or salt solution on the sensor.
  4. Seal the jar. Plastic wrap and rubber bands will do. Allow some time (2 to 6 hours) for the air inside the sensor to reach the proper relative humidity level.
  5. Repeat with a different salt will add confidence in your results, and help eliminate testing error.
  6. If your sensor doesn’t repeat within ± 3% RH (since that is about as good as they get at our price point), something is fucked up—your testing procedure (is your temp accurate), or your sensor!
image

Honor is simply the morality of superior men.

 
Posted : October 20, 2022 9:06 pm
Bangswitch2A, Stootie, Macky and 2 people reacted
im_sparky
(@im_sparky)
Posts: 2896
Limonene Moderator VIP
Active Grow Diary Bling
Patreon Bling
Discord Member
3 Complete Grow Diaries
10k Post Likes
1k Posts Bling
Cali Cowboy Grow Off Bling
1 Plant of the Month Win
Moderator Bling
Member for 2 Years
The High Council Award
 

@sevans1965 Good info, bro! Thanks for sharing that. I'm going to check the calibration of my unit.

 

To see a World in a Grain of Sand, And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand, And Eternity in an hour.
― William Blake

 
Posted : October 20, 2022 9:31 pm
Stootie, Macky and WoodI2 reacted

Our forum is free to join. We are an international cannabis forum that helps people all over the world grow their own personal supply of cannabis. Through our site you will find cannabis breeding forumscannabis deficiency forumsindoor cannabis growing forums, and much more. 

We are a home growers cannabis forum, and we only allow people who grow cannabis for personal use to be members. Our mission is to help you grow your own cannabis. We do not buy/sell/trade cannabis, or equipment for growing cannabis. Our site is strictly a cannabis smokers forum, cannabis growers forum and forum for medical cannabis users.

Use our guides on how to grow cannabis, cannabis grow diaries, and growers forum to find all the info you need to learn how to grow your own cannabis.

Any member who is suspected of growing cannabis for commercial gains will be banned immediately.

Please read our forum rules, and enjoy the site.

Find us on all social networks! Just search for Percys Grow Room