Where to measure Humidity?

[broderp]

As the topic states, Where do you measure humidity?

I read care sheets and they all say the same basic thing:

• Humidity should be between "X"% and "X" %
• Humidity should vary through out the day.

This much I get and under stand, but WHERE do they recommend this be read from?

• The basking spot?
• Middle of the upper most spot dead center?
• Opposite side of the basking spot?
• The middle of the enclosures height on the right side?
• The middle of the enclosures height in the center?
  
• The middle of the enclosures height on the left side?
  
• The lowest point of the enclosure on the right side?
• The lowest point of the enclosure in the center?
  
• The lowest point of the enclosure on the right?
  
• Some wheres else less obvious?

Since we are aiming for a temp gradient, and all that fun stuff, how does this play into the humidity? Stating a recommended humidity without stating where the highest and lowest point is like shooting at a target with a blind fold.

 

[Virgil1972]

I put my probe in a spot where it does not get sprayed.

 

[Turkenheimer]

To add to the confusion...

Air at 70°F and at 50% RH gives us a dew point of about 50°F. That same moisture content in that air heated to 85°F is only 30% RH!

That is the SAME moisture content in the air, but only warming the air reduced the RH by about 20%. At 95°F and RH of 50% moisture will condense at 74°F!!!

So Relative Humidity is sort of a red herring.

Hygrometers are typically calibrated at 68-70°F so they are usually most accurate at that temp (they are notoriously inaccurate... if you don't believe me, try the Salt Test).

So, if you are advised to keep the RH at 50% or higher, you want that at "Room Temperature" not at 85 or 90°F.

So, put your hygrometer in a place that represents the air-flowing through your chameleon's habitat, the room's air.

 

[broderp]

To add to the confusion...

Air at 70°F and at 50% RH gives us a dew point of about 50°F. That same moisture content in that air heated to 85°F is only 30% RH!

That is the SAME moisture content in the air, but only warming the air reduced the RH by about 20%. At 95°F and RH of 50% moisture will condense at 74°F!!!

So Relative Humidity is sort of a red herring.

Hygrometers are typically calibrated at 68-70°F so they are usually most accurate at that temp (they are notoriously inaccurate... if you don't believe me, try the Salt Test).

So, if you are advised to keep the RH at 50% or higher, you want that at "Room Temperature" not at 85 or 90°F.

So, put your hygrometer in a place that represents the air-flowing through your chameleon's habitat, the room's air.

So after my head stopped spinning, I reread your post. Looks like humidity is a moving target. I need to figure out where in the terrarium is about the same temp as the room air, and measure the humidity from there and adjust as required. Right?

This would be tough to keep very accurate. One would need multiple temp sensors including one reading the room temp and a program monitoring this at several locations within the enclosure. You would also need to have as many humidity sensors and read only the one ties to the temp sensor that matched the room.

This will make positioning my humidity monitor rather tough.....

 

[xrowdac]

just simply put 2 monitors above & below....wherein the bottom parts is usually stable (GLASS CAGE)

 

[broderp]

just simply put 2 monitors above & below....wherein the bottom parts is usually stable (GLASS CAGE)

I'll have two sensors monitoring humidity, that's the easy part. I only have one that actively will turn on my humidity controller or mister should the humidity drop below the safe zone and need to be boosted.