Boveda One Step Hygrometer Mess Free Calibration Kit – Preloaded 32% RH 2-Way Humidity Control – Hygrometer Accuracy – Precise Test for Digital and Analog Hygrometers and Humidity Sensors – 1 Count

I'm in the process of designing a product that measures the temperature and humidity of beehives. There are plenty of temperature sensors on the market that are cheap and accurate, but humidity sensors are generally pretty expensive in comparison and, as I've discovered, wildly inaccurate.Having purchased a sensor that I had some confidence in, I needed to test it. I created my own testbed, with very accurate control of temperature, but I needed a way to accurately define a level of humidity.There are a plethora of YouTube vids on the subject demonstrating how this can be achieved using a home-made salt solution in a bottle cap, but even having purchased some lab-grade sodium chloride and distilled water my results were all over the place. It was while I was doing more research along these lines when I can across some adverts for Boveda products in relation to maintaining the humidity in humidors, a cupboard for cigars.Looking at the Boveda website I discovered that they produce larger product packs for cigars, but also produce smaller packs with high tolerance chemical solutions that can be used for hygrometer (an instrument used for measuring the amount of humidity and water vapour in the atmosphere) calibration and purchased a pack.The Boveda One-Step Hygrometer Calibration Kit allows a high degree of reliability, with a high degree of accuracy simply by placing the hygrometer, or in my case the sensor, in a small airtight container. The kit comes complete with an air-tight plastic bag and the Boveda humidity pack. To use it, you just put the device to be tested in the bad and let the humidity in the bag settle for 12 hours or so, it's as simple as that.In my case, I placed the sensor in a small bag, sealed the bag around the wires from the sensor and placed the whole pack into my chiller. At a consistent 21.5 DegC (+/- 0.3 DegC), I let the sensor soak for a day and then analysed the results.Long story short then, the results where excellent. Incredibly stable humidity results, at exactly the level I was expecting, well within the tolerances stated by Bovida and the sensor I was calibrating during my experiments. I certainly won't be mucking about with salt solutions any more.My only regret is that I've spent a fair amount of money of lab-grade chemicals and that my better half is getting peeved with the 1Kg of salt that's taking up cupboard space. Still, I guess I can use it on my fish & chips?

The instructions say keep the item to be Calibrated in the bag at room temperature of between 65F and 75F. This is a big tolerances and as R/ H changes as temperature rises or falls I cannot see how this can be so accurate.I setup my unit midd way at 21⁰C and hope for the best.

Going back to first principles in a standard package - it was brilliant for a small wireless humidity sensor. I bought a pack of low and high RH and was able to check two sensors at low and two sensors at high. I have not yet swapped the sensors to do both sets of readings but would seem to be easy to do. Only complaint is that I would like a larger plastic sleeve in order to test larger sensors. And what to do about sensors that have wire connections to a controller?

Very much the easiest way to recallibrate hydrometers. Can check multiple devices one after the other. Fast delivery and good price

As described.

This is the 4th time I have used this kit. I buy a new one every time I set a humidore up for a friend. It is suprising how off some hydrometer are. This works great every time to get them dialed in.

My wife binned this by accident, it was a touch too small anyway. I now just use any zip lock bag and buy the packs separately.

Seems to work ok