How accurate and do you want to have logging capability?
For just peace of mind, a cheap unit from a big box store or amazon would work.

For more accuracy and logging, I use Sensor push sensors in my humidor. Govee gets decent marks as well from some other cigar guys.

 

When I needed an accurate Therm/Hygro reader to monitor the conditions that made my new windows sweat, I spent the extra money for a "traceable" unit--meaning that it meets certain laboratory specs.

It cost about $100 in 2017, but it maintained consistent readings--and always refuted the random readings of the cheap versions used by the window-company's representatives.

I see that the price is now considerably higher, but I'm sure there are other "traceable" alternatives out there:

Fisherbrand Traceable Relative Humidity/Temperature Meters - Humidity and Hygrometry, Hygrometers

Monitor air conditions in environmental chambers, chemical storage areas, cleanrooms, incubators and stockrooms

www.fishersci.com

 

You could get one of the multifunction gizmos that test for particles (dust) and off gassing too. A way to know when you should don or can doff your mask. Old words eh. Along the lines of the link below.

Air Quality Monitor Portable Outdoor and Indoor Professional Air Quality Monitor Pollution Meter for Home, Office, School, Hotel, Car (White) : Amazon.ca: Industrial & Scientific

Air Quality Monitor Portable Outdoor and Indoor Professional Air Quality Monitor Pollution Meter for Home, Office, School, Hotel, Car (White) : Amazon.ca: Industrial & Scientific

www.amazon.ca

Pete

 

I have a cheap AcuRite one in my office that works quite well. I believe I got it at HomeDepot years ago for cheap. It shows current temp and humidity and keeps track of the high/low of both, so you know what your fluctuation range is. Here is one on Amazon for about $11 with a slightly different case than mine (same data and face though). Oh, and I purchased mine at least 4 years ago and it's still working fine on the same (AA) battery, so battery life is excellent.

Cheers,
Brad

 

Any Hardware Store carries them. I was looking at the ones from Menards about a month ago. They had a large selection of styles. I was thinking of dismantling the gauges from the original casing and mount them into a 1"x6"x9" wall hanging plaques to sell them at crafts shows. Prices were low enough to do it.

 

I use Acurite in the house to monitor temps and humidity in 6 different rooms, one being the garage and one the attic. Nice thing about this is if you get the Hub, you can watch the numbers on the web or on a smart phone using an app. It is especially handy when I heat the garage up, I can see when it's warm enough to go to work without leaving my recliner....

 

I'm thinking that if you need accuracy, you need at least 4 calibrated units. One in each corner and compared frequently with each other to see if there are variations.
If you only have one, how do you know how far it's off from reality ??

 

If it is for your shop, high level of accuracy is not really needed. I found d a lot of good ones on Amazon. This one is better than 4.5 stars with over 135, 000 ratings and $11. It would be good enough for me.

 

I rolled my own. It both monitors and records temp/humidity/barometric every 15 minutes as well as daily min/max and time of all three. I have free, complete plans online.

It's a couple hundred bucks of Arduino parts but works great! I even have a CNC file to drill the panels and all the 3D .stl files to print the mounts and odd bits.
I even wrote software to plot the results.

Project links here and here

 

You can get a 6-pack of smaller humidity/temp readouts for under $15. I use them in humidors and they work well and accuracy is decent.

You can also get a round version which I prefer (single vs two batteries), but they are currently out of stock)

 

Yeah, used those on humidors too.

But for real fun I made this one:

 

This is what I've been using for a year or so: ThermoPro TP55 Digital Hygrometer Indoor Thermometer Humidity Gauge with Jumbo Touchscreen and Backlight Temperature Humidity Monitor in White

 

I have a cheap weather station (Ascot). It has sensors in the panel and can show results of 3 remote sensors (one at a time).

• when all the remote sensors are in the same place, they don't give the same indications.
• the indicator panel has 3 levels of back lighting (1 off and 2 lighting). Obviously the lighting dissipates some heat as the temp indicated by the sensor in the panel change with the lighting level.

Not very accurate but, assuming it is repeatable, one could have a calibration chart for each sensor. You would need a calibrated thermometer for comparison.

For humidity calibration one would need 2 calibrated thermometer, one dry, one wet and a psychrometric chart.

The sensors have some inertia and need some time to stabilise.

 

I purchased three of the Accurite units. One still works. I purchased two of the ThermPro units. Both still working fine after 3-4 years, recommended. The temperature on these products will be at most a degree off, but humidity is much harder to measure accurately. I am happy if they are within 5-10% of my HVAC meter, a UEI DTH35, which is supposed to have 3% humidity accuracy. Note that the humidity reading will usually take longer to stabilize when the unit is moved to another room than the temperature.

 

I have been searching for something related but slightly different.

We do not need a hygrometer or humidity readings. What I need is two displays in the house that receive outside temperature from an outdoor battery-operated (or solar?) sensor that transmits to them. The displays should show inside and outside (sensor) temperatures in large digits and not much else. (Date and time in small digits is okay.) All we really want is to look from across the room and know the temperature inside and outside.

For many years, we have used two La Crosse brand displays that worked for us, model WS-9080U-IT. They fail every few years. Worse yet, any time that one needs batteries, I must bring them all together and reset all three simultaneously so they "listen" to the sensor. I have grown tired of the unreliability and the awkward setup that happens too often when a battery fails.

I don't want to wire and setup a full weatherstation. All I want is something low cost and simple to use. Can you recommend something like that?

 

No matter what model we get, how do we calibrate it ???
How and when do we know that it's only a fraction of a degree off or 20 degrees off ?

 

Aboveboard, you might try the Thermopro units. They don't usually have to be next to one another to re-sync after a battery change, and the one I have will work with three remote units.