hygrometer/thermometer

hello, i bet most of you have sat looking at your temperature and humidity measuring device and wondered "how do i know if this is telling me the truth?" having "faith" that your instrument is correctly calibrated is never a wise thing to do as i have 3 bought at the same time, two made by the same company that all give different results.there is a very simple way to test your hygrometer using salt, water and an airtight container. these guys explain it better than i ever could so here is a short instructional video. https://youtu.be/d2XWnVP3gaI

when it comes to knowing your temperature, for most accurate results use a good quality scientific glass, alcohol filled, mounted thermometer to test your digital ones against. then if there is a difference you can mark your thermometer +/- to compensate for it.

when measuring air temp in the space it is critical to have your thermometer in the shade as the radiant heat from the bulb can cause warming of your devices casing and skew your results (make a little hat if you have to). i find the best way to know the temperature at canopy level is to use an infra-red lazer thermometer i got mine from fleabay for about a tenner with free postage.

i hope this helps as having your temperatures and humidity dialed in can be the difference between good and wow that was amazing pot.

youre welcome. 

no i never opened them up to see if they could be manually adjusted. i have marked them though to give me a better idea of how close i am as no device is ever perfect and usually have a 5% +/-  tolerance anyway.  

I dont even have one! 

i hope for your two sakes you never get struck with the big B. lowering humidity in the last weeks of flowering increases resin production to help seal up the plant against water loss through transpiration. more resin production = more potency. humidity spikes midway through flowering increases chances of being struck with Botrytis. if you dont measure it how do you know when its a problem? i run my fans 24hrs to deal with the lights off humidity peak and have a dehumidifier in the room that the tent is in so if i start seeing humidity numbers i dont like i just switch it on and keep an eye on things till the balance is restored.