SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration
Original price was: $18.99.$17.09Current price is: $17.09.
Price: $18.99 - $17.09
(as of Aug 10, 2025 15:06:21 UTC – Details)
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SMARTRO
Once you have it, you’ll love it!
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SMARTRO is devoted to creating the intelligent electronic home and kitchen products such as weather stations, projection clocks and meat thermometers etc.
Equipped with professional technical team and after-sales team, SMARTRO cherishes every feedback and comment on the products so as to get improvement accordingly. Our aim is always to provide the best shopping experience for our customers!
Alarm Clocks & Weather Station
In/ Outdoor Thermometer
Why Choose SMARTRO?
SMARTRO has decades of experience in home and kitchen tools. We pay much attention to the product quality and using experience of our customers.
We have always been providing the best after-sales service, as customers’ satisfaction is our first goal!
What makes our products unique?
SMARTRO has been always looking for the perfect combination of the technology, home and kitchen life. And we have been also committed to developing more excellent products to our customers.
We hope that people who use SMARTRO products can enjoy the efficient cooking method as well as a healthy life.
Product Dimensions : 3.4 x 1.18 x 3.4 inches; 4.59 ounces
Item model number : SC42
Batteries : 2 AAA batteries required.
Date First Available : October 10, 2019
Manufacturer : SMARTRO
ASIN : B07YY1FB9D
Best Sellers Rank: #2,721 in Patio, Lawn & Garden (See Top 100 in Patio, Lawn & Garden) #4 in Weather Hygrometers
Customer Reviews: 4.6 4.6 out of 5 stars 6,618 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
The Best Industrial Grade Accuracy: Humidity gauge with built-in Swiss sensors, it detects subtle humidity and temperature changes and updates readings in each 10 seconds. Temperature tolerance is within 0.5℉(-4 to 158℉) and humidity is 2%RH (1 to 99% RH). The digital hygrometer is pre-calibrated for accurate temperature and humidity measurement.
Easy-to-Read Backlit Display: Temperature and humidity monitor with 3.5” large HD LCD screen. A simple touch on the top will turn on backlit for 10 seconds. Clear and power-saving, reading more easily under weak backlit. Reliable operating buttons on the back for manual setting or °F/°C switching. Note: The backlit in the pictures is all in ON state. The backlit is not always on.
24 Hours All-time Max Min Records: The room thermometer displays high and low records for the past 24 hours and All-time; Indoor thermometer measure conditions and identify changes in temperature and humidity instantly. Comfort Indicator ensures proper humidity control, helping you to maintain a comfortable atmosphere in your home.
Wide Applications with More Mounting Options: With a retractable stand, two powerful magnets and a wall-mount hole, this digital thermometer indoor can be easily attached to your refrigerator, wall or placed on a table. Suitable for baby’s room, nursery, office, closet, incubator, greenhouse, garden, wine cellar, basement critter terrarium etc. Note: This thermometer cannot connect to phones.
Calibration Supported: The monitor can be manually calibrated to improve data readings when product placement or environmental factors impact your data accuracy. Powered by 2×1.5v AAA batteries (not included).
Customers say
Customers find the humidity meter highly accurate, showing high and low temperature readings, and appreciate its easy-to-read display that’s visible from across a room. The device features a large display, is simple to use, and includes a useful backlight that brightens with a push of a button. Customers use it effectively in woodshops to monitor conditions, and one customer mentions it helps control humidity levels as temperatures change. The build quality receives mixed feedback, with some customers describing it as well-made while others report it breaking after a month of use.
13 reviews for SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer Room Humidity Gauge Pro Accuracy Calibration
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Original price was: $18.99.$17.09Current price is: $17.09.
JayPee –
Good Device
Most of these devices seem to use the same screen layout. I chose this one because the numbers are big and bold and easy to read. It has a soft touch light control on the top – just touch it gently and it lights up. It has two strong magnetics. This one is attached to my fridge.In the description, it states the device is calibrated. I assume using international standard of calibration? I have no idea.However, most of the time it matches or is within one tempt degree of my furnace thermostat and my other brand new hygrometer (Acurite). The humidity reading matches the Acurite. I decided to use two different companies for comparison.To conclude, I like the device and would recommend it.
David G. Parkhurst –
My fave
Great unit! You can actually calibrate these as far as humidity goes. Seem to be fairly accurate and easy to read.
BSL –
Its ok
It works, I like it can be calibrated
Brandon –
ComprehensiveTemperature and Humidity Monitor
I love the SMARTRO SC42 Professional Digital Hygrometer Indoor Thermometer. It tracks humidity and temperature accurately and provides high and low figures to show the range, along with a colored bar that indicates whether the current levels are Low, OK, or High. Living in Colorado, where it’s quite dry, this monitor has been invaluable for keeping track of the humidity in my room to ensure that I run my humidifier just the right amount. The clear display and easy-to-understand indicators make it a fantastic tool for maintaining a comfortable environment. I also like that when you touch the screen, it turns on a backlight for times when viewing in the dark. Whether you’re concerned about temperature or humidity, this monitor give you all the information that you need at a glance at a bargain price.
Gilbert Herman –
Works great
Nice display, like the 24 hour high/low reading, very sensitive to humidity changes, great price, arrived fast
Ed John –
Great display, appears to be accurate, my new go to
Great display. Seems to be accurate. My new go to for humidity monitoring.The first order I got (2 items) one of the screens was dim. The replacement arrived in no time at all and it was in perfect working condition.Iâm in Florida and have bought dozens of these devices over the past 10 years. These are the best so far.
Stella –
Works well, seems to be accurate!
I bought this hygrometer to verify the humidity in my new humidor. While I havenât performed a salt test to verify the accuracy of this meter, I did place it next to both my ac/heat controls and both the temperature and humidity were spot on for all three instruments. The response time for this meter is a few seconds.This meter works as described. You can adjust the calibration if needed. The directions are simple and clear. I really canât say anything negative about this hygrometer. As for my humidor, that meter needs replacing, but that is another reviewâ¦
Neosho Valley –
Company Stands By Their Product
The display is bright and easy to read. I haven’t run a calibration (which it is capable of) but from my experience, the accuracy feels right on. I use this in an egg incubator and it works great. After purchase last December, I didn’t hatch any eggs right away. In late February, we set up the incubator with the thermometer/hydrometer inside. Everything started fine but before the 21st day, segments of the hydrometer faded out. I EMAILED THE COMPANY WITH MY PURCHASE INFORMATION NEARLY 4 MONTHS AFTER BUYING IT ON AMAZON AND THE CUSTOMER SERVICE REP’S REPLY WAS “WE’VE MAILED A NEW UNIT TO THE ADDRESS IN YOUR EMAIL.” There were no questions, no photos required, no returns; nothing, just great customer service! I think I have a winner here and if needed, I will absolutely purchase one of these again.
Tom –
I brought one checked it via a salt test bang on 75% brought another same as bang on 75%. Very pleased with the accuracy, very easy to use & has a decent magnet to hang up. to verify if your meter is correct put it in a plastic container with a cap filled with salt add a very small amount of water to the salt so you can still pick it up & it doesnât run, seal it properly leave it a full 24hrs and it should read 75% if not itâs out & needs calibration )
Meri –
He tenido muchos de estos y este es muy preciso, además se ilumina al moverlo, vale la pena el dinero q vale.
Adamo –
Working great so far and Iâve had for a few months now. Accurate measure and backlight is very bright but not blinding. Great display and easy to read.
Xavier A –
It didn’t update as quickly as I expected it, but the product is generally accurate. The display is excellent; easy to read and very functional. I love the various features (record high/low, C to F, temperature/humidity trends, and manual calibration), too!
Lorna Yeo –
The product was shipped really well and quick. Overall, really easy to use, just need to install 2 batterys and its good to go. Magnet on the back is also strong, so it sticks well to surfaces. Only thing is that the display picture suggests that the sensor comes with a kickstand, which was not on the sensor when I got it. So if you’re looking for something that has a kickstand, or can stand on it’s own, maybe check with the seller first.