Lovely and straight forward. I've been reading about humidity measurement today and the maths. Better understanding will be to start with this device me thinks.
Great video! I think towards the end of the video there is a mistake in the input data for the computer calculation of the relative humidity: Dry bulb > Wet bulb temperature
Is this table the same for any type of wet and dry bulb thermometer ? Then it would presumably just need a slightly different time for the wet temperature to reach it's particular end value. Doesn't the temperature keep droping if you spin it even faster and longer ?
The rate of evaporation and therefore the wet bulb temperature will be dependant on the velocity of air over the wet surface. They suggest that a whirling hygrometer is rotated at 180 rpm (2 revs per sec). The air flow over the material in a static wet / dry hygrometer is very uncertain and I would suggest this would give an inaccurate reading. Perhaps a unit installed in a Stevenson Screen can be calibrated for static use, but you would still be better to consider wind speed as one of the factors in the calculation.
bob bob bob bob bob bob bobm bob sdfghjhgfdsasdfghjklkjhytrertyuikl;'oiuytrdfghjkl;';lkjuygtrtghjkl;';lkjgfdsfghjkl;lkiuytrfghjkloiuytredfghjklp;';lkijuhytfrdeswdrtyuiop;loiuytghoplokijuhygtfrdeswedrftghyujiklokiuytredfghjuikijuhytrertyuiuytrtyuiolploiuytre jythyghy
This just show you the principle. I think it needs alot of parameter standard to be accurate though. Like how wet the bulb needs to be and the rpm. But i learned something today, thanks.
I have a question, I have a cheap but accurate thermometer, I take note of the temp, and stick wet cotton on the bulb, and swing it for a min, then take the temp again.. I know it is supposed to be with 2 at the same time maybe to be more accurate, but really the difference between my reading when it is dry and doing the experiment is one min, in the same spot, should that give me accuracy? when I do it, my room temp is 28, I swing it with wet cotton on the bulb for a min it comes to 26 only? does that mean I have 85 of humidity? we have 10% humidity outside, so I placed wet towl near the AC to increase humidity but I do not feel soggy at all.. where is the mistake? why it has to be 2 thermometers. swung at the same time..? one thing though the bulb is protected with little metal grid with 3 opening could that be the factor that give me this mistake? thanks
Humidity density can be over 100% it’s not the quite calculated when there’s fog it’ll show 100% but there’s different densities a fog as well so you need to be able to measure the rate of flow of the condensate to calculate actual humidity levels. The cold mirror hydrometer should be more used.
Sir using the wet and dry bulb to determine the humidity inside the egg incubator, is the difference between the two thermometers is the humidity we need to know or do we need a chart to determine it ?if we need the chart can you show us please . thanks
No - Relative Humidity can only be in the range 0% - 100%. The maximum mass of water in the air changes with temperature. If the temperature drops below the point where the humidity would be over 100% the water will drop out as dew on surfaces or mist or rain.
You can easily measure the humidity over 100% percent in a measuring beaker. If there fits 1.2 litres in a 1 litres beaker you got 120% of humidity. ;D
Ctw 7prime A J-cloth is just an ordinary household cleaning cloth - the cheap disposable ones.. J-cloth is actually a brand name of the Johnson & Johnson company.
Humidity is so high where I live. Average RH is 85% during summer season. To counter this I keep a mini dehumidifier in my room to suck in about 60%-70% of moisture in the air. It does make a big difference. A combination of a good ceiling fan and a dehumidifier makes the atmosphere inside the room almost feel like an AC room.
You can attach the thermometers to the bottle with anything you like... tape of any kind is just an easy option. Use string if you want.. or glue whatever !
If i understand your question correctly: Don't do anything to the dry bulb. Just tape it to the bottle. For the wet bulb, I believe he said to use cotton wool (cotton ball), or J-cloth
Cool experiment, horrible combover. My suggestion is to throw caution to the wind and let that beautiful skin helmet show, after all, hair loss means hyper testosterone! (Seriously man, check out :55 seconds, yowza!)
Never learned this in school. At least not the mechanics of how a hygrometer works. Thanks for this video. Learned something new today.
Lovely and straight forward. I've been reading about humidity measurement today and the maths. Better understanding will be to start with this device me thinks.
Thank you Michael Caine!...very beautifully explained video..
Great video! I think towards the end of the video there is a mistake in the input data for the computer calculation of the relative humidity: Dry bulb > Wet bulb temperature
Now that is an interesting experiment. Can you do a video to accompany this about the history of hydrometer readings and how it came about.
Hi
Is this table the same for any type of wet and dry bulb thermometer ? Then it would presumably just need a slightly different time for the wet temperature to reach it's particular end value. Doesn't the temperature keep droping if you spin it even faster and longer ?
Amazing. I'll make one.
I love your knowledge.... how could we support you?
Smart explanation. It was informative indeed.
Thank you very much, I'm really grateful to you.
excellent, thank you
Cn you use digital thermometer?
This was a very interesting video. I plan on making one even though I have instant access from my phone.
The rate of evaporation and therefore the wet bulb temperature will be dependant on the velocity of air over the wet surface.
They suggest that a whirling hygrometer is rotated at 180 rpm (2 revs per sec).
The air flow over the material in a static wet / dry hygrometer is very uncertain and I would suggest this would give an inaccurate reading.
Perhaps a unit installed in a Stevenson Screen can be calibrated for static use, but you would still be better to consider wind speed as one of the factors in the calculation.
Worcester Exchange 3 revs not 2
bob bob bob bob bob bob bobm bob
sdfghjhgfdsasdfghjklkjhytrertyuikl;'oiuytrdfghjkl;';lkjuygtrtghjkl;';lkjgfdsfghjkl;lkiuytrfghjkloiuytredfghjklp;';lkijuhytfrdeswdrtyuiop;loiuytghoplokijuhygtfrdeswedrftghyujiklokiuytredfghjuikijuhytrertyuiuytrtyuiolploiuytre
jythyghy
This just show you the principle. I think it needs alot of parameter standard to be accurate though. Like how wet the bulb needs to be and the rpm. But i learned something today, thanks.
Not really, that is the beauty of this method, such parameters need not be precise.
thank you! this will save me some money.
But what about the spead of whirling?
How did you get that chart?
google the psychometer chart
Thanks alot!!! I needed something as cheap as this.
I have a question, I have a cheap but accurate thermometer, I take note
of the temp, and stick wet cotton on the bulb, and swing it for a min,
then take the temp again.. I know it is supposed to be with 2 at the
same time maybe to be more accurate, but really the difference between
my reading when it is dry and doing the experiment is one min, in the
same spot, should that give me accuracy? when I do it, my room temp is
28, I swing it with wet cotton on the bulb for a min it comes to 26
only? does that mean I have 85 of humidity? we have 10% humidity
outside, so I placed wet towl near the AC to increase humidity but I do
not feel soggy at all.. where is the mistake? why it has to be 2 thermometers.
swung at the same time..? one thing though the bulb is protected with little metal grid with 3 opening could that be the factor that give me this mistake? thanks
Thanks, excellent explanation and demo.. Nice job
Humidity density can be over 100% it’s not the quite calculated when there’s fog it’ll show 100% but there’s different densities a fog as well so you need to be able to measure the rate of flow of the condensate to calculate actual humidity levels. The cold mirror hydrometer should be more used.
Sir using the wet and dry bulb to determine the humidity inside the egg incubator, is the difference between the two thermometers is the humidity we need to know or do we need a chart to determine it ?if we need the chart can you show us please . thanks
how do they measure humidity over 100% ? when i lived in Houston, there were many days it would be close to 120%
No - Relative Humidity can only be in the range 0% - 100%.
The maximum mass of water in the air changes with temperature.
If the temperature drops below the point where the humidity would be over 100% the water will drop out as dew on surfaces or mist or rain.
You can easily measure the humidity over 100% percent in a measuring beaker. If there fits 1.2 litres in a 1 litres beaker you got 120% of humidity. ;D
Can i just ask
What's the thing he puts in 1 thermometer
Thanks good information
Would be good if you had a separate video on how to measure.
just read a psychometric chart
The video explained clearly how to measure.
What's jay cloth?
Ctw 7prime A J-cloth is just an ordinary household cleaning cloth - the cheap disposable ones.. J-cloth is actually a brand name of the Johnson & Johnson company.
Thank you very much sir, very useful
loved the explanation!
How do I hook this up to my Arduino MEGA 2560?
what no mention of Psychrometric Charts
do we need to use electrical tape
Humidity is so high where I live. Average RH is 85% during summer season. To counter this I keep a mini dehumidifier in my room to suck in about 60%-70% of moisture in the air. It does make a big difference. A combination of a good ceiling fan and a dehumidifier makes the atmosphere inside the room almost feel like an AC room.
You can attach the thermometers to the bottle with anything you like... tape of any kind is just an easy option. Use string if you want.. or glue whatever !
great video
Good knowledge
Which thing to stick for dry bulb. I can't here properly
If i understand your question correctly:
Don't do anything to the dry bulb. Just tape it to the bottle.
For the wet bulb, I believe he said to use cotton wool (cotton ball), or J-cloth
um why not just get a hygrometer at the pet store instead of the two thermometers to make the hygrometer.
Brilliant idea. Loved it.
Superb
LOL Very interesting!
👍👌
Thank you so much! It was informative indeed.
hey i learned this in thermo
i just realized that the guy in the video worked 30 years in met office
met?
Michael Caine?
Stodoys has very good designs and plans.
Cool experiment, horrible combover. My suggestion is to throw caution to the wind and let that beautiful skin helmet show, after all, hair loss means hyper testosterone! (Seriously man, check out :55 seconds, yowza!)
Why ih yeah yeah
I made it by myself. I used woodprix woodworking plans for that.