SC92 Professional Indoor Outdoor Thermometer Wireless Digital Hygrometer Room Humidity Gauge Temperature and Humidity Meter Pro Accuracy Calibration

I bought this in 2021 for its ability to measure down to 1% RH. My use case is measuring RH in a dry box for FDM 3D printing filament, where low RH is critical for filament storage and usage. These sensors have performed flawlessly for the last 5 years, and I suspect will perform similarly well for years to come. Battery life on these things can easily be measured in years, I don't remember the last time I needed to change the batteries. Each one needs 2 batteries, the outdoor sensor needs AA, and the indoor needs AAA. The only VERY small thing I can find wrong with these two sensors is that it takes a while for the outdoor sensor to update the measurement on the indoor one, its probably at least a few minutes. But that is a nonissue for most people and the update rate directly effects battery life of the outdoor sensor, so most people won't care. What really pushed me to make this review was doing a tear down of the outdoor sensor and investigation of the components inside. The sensor for temperature and humidity is a Sensirion SHTC3, which is a fantastic sensor. They are calibrated against a standard which has a NIST traceable calibration. It is likely that you will never need to do a calibration yourself either, even after 10 years the humidity sensor will typically only drift by +/-2.5% and the temperature sensor by +/-0.36f. And from some limited testing after 5 years between the outdoor and indoor channel the RH measurement only differs by 2% and the temperature measurements are the same. Pricing wise, if you wanted to remake just the main electronics from one of these sensors (display, sensor, mcu, battery holder, and radio) it would cost more than the product as a whole. So its great value for money. Overall, if I need a countertop hygrometer/thermometer I wouldn't hesitate to buy a Smartro product and I would recommend this product if anyone else needs one for their dry box.

The strengths: This digital thermometer is inexpensive, conveniently sized and the installation straightforward and easy. By cross-checking with my old-fashioned liquid thermometer, it also appears to be very accurate and did not require further calibration out of the box. The Bluetooth connection to the remote sensor paired easily and works well despite building wall barriers. MIA: WiFi connection to allow remote monitoring of temperature and humidity.

UPDATE - Vendor contacted me and offered to replace the sensor. I did so, and now the setup is working fine. I still think the setup procedure is somewhat awkward, and could be better explained in user guide. After getting it setup, though, it is easy to use and provides clear, well organized displays. This, plus the vendor support get a rating upgrade to 4 stars. ----------------------- ORIGINAL - If it worked as advertised I would give it only a 3, since the design of the transmitter is quite poor. A tiny channel selection switch inside the the transmitter is supposed to select a communication channel (1,2,3). My unit came with the switch set to 2, and I could not switch it to a different channel. Could be defective switch. Anyway I have no problem with using channel 2. When I followed the Rube Goldberg setup procedure with transmitter and receiver next to each other, I got an "outdoor" reading. But when I placed the transmitter outdoors (30 ft away) the outdoor reading went blank and has stayed that way. The display unit is easy to read (bright, good contrast). If only it had something useful to display...

Full disclosure, this product was provided by the manufacturer, with the aim of providing a thorough evaluation/review. The monitor arrived in good order in compact packaging. The manual is easy to follow and succinct. The remote station requires two AA batteries and the indoor monitoring station requires 2 AAA batteries. I would like to have had the batteries provided, especially considering they are different types, but for the price I don’t think it’s a big deal. Both units immediately powered up and linked up with no issue. I would like to have the receive signal intensity noted on the display, to ensure I hadn’t paced the remote station too far away. The manual states it has a 200ft range. I placed the unit <100 feet for this test. I placed the remote station outside on a screw, under the eave of my garage, as the manual states it is not water proof. Additionally, the unit faces north, but it’s on a west facing side of the house. I live in Texas, so the afternoon heat will really put this product through its paces. We had 107°F temperatures this past week! After a couple of days, I relocated the sensor to the north side of the house, and the temperature reading were more accurate, i.e. don’t place in direct sunlight. The base station has a stand that opens and closes, so it can sit on a table. The nicest touch are the magnets on the back, as I was able to just “stick” it to our refrigerator. After placing the remote unit outside, I did note there was a slow update rate between the remote and base station, as their values didn’t concur. I also noted there was a significant acclimation period once the device was placed outside. For on-going monitoring, I don’t see this as an issue. If the update rate is slow, it’s likely at a pace relevant to the rate of change throughout the day and would also prolong the battery life. Overall, I’m very happy with this product. It’s a nice looking, simple and straight forward tool to know the temperature and humidity inside and outside. It worked flawlessly during the week-long evaluation. I will continue to use the device and gain a better assessment of it’s durability. PROS: • Bright, colorful, and easily read display • Very easy set up • Magnets on the back of the base station make for convenient mounting to a metal surface (e.g. refrigerator) CONS: • Batteries not included • Does not measure barometric pressure

This is a great indoor /outdoor thermometer. Highly recommended. It's a good size, mounts easily, especially with the magnet on back for affixing to a refrigerator, etc. . Two things to consider. The sensor is not waterproof. Best to cover it in some way or, at least, keep it out of heavy rain or snow. Mounting the sensor in a sensor shield is a good idea. Shield is available on Amazon web site for $10, and this will prevent sensor damage. Another issue. Be sure to install lithium batteries in the sensor if you live in a very cold climate. Regular alkaline batteries will only work to about minus 20 degrees. However, do not install lithium batteries in the thermometer itself. Lithium batteries produce 1.8 volts per cell when new. This will cause a shadow in the read-out, because pixels are being illuminated in the background by the higher voltage. I doubt if harm could be done, but it makes the display hard to read. Install regular alkaline batteries and the display is perfect. Alkaline batteries produce 1.5 volts per cell, and I believe the thermometer is designed for this voltage. Overall, this is a really good indoor/outdoor thermometer if the correct batteries are used.

I am thus far (2 weeks) quite impressed with the performance of the SMARTRO SC92 unit. Purchased the sensor/receiver package along with 2 additional sensors. After selecting channels and inserting batteries, synchronization occurred quickly and, over a 2-d period, no loss of sensor signal reception was noted. In testing accuracy, all three sensors, when clustered, presented nearly identical readings, +/- 0.1 °F, RH: +/- 4 percentage units. The temperature readings were spot on with that of a lab-quality mercury thermometer. For routine operation, I have 1 sensor in a shaded ‘sun’ room, and 2 at outdoor locations on my property, the most distant at nearly 150 ft from indoor receiver. The distant unit, away from protection of eaves and exposed to elements (rain, yes, but no direct sunlight), is housed in a sensor-protection shield, available from Amazon (under $20). Although the shield is from a different manufacturer, it’s available as a stand-alone purchase (no sensor, no receiver) and readily accepts the Smartro sensor, requiring no modifications. The ability to place a sensor away from the influence of heated structures (e.g., house, outbuildings) fulfills my need to monitor temperature in locations that might require measures to protect cold-sensitive plants. (And yes, a few degrees can make a big difference with sensitive plants). The shielded sensor was 1-week ago exposed to 12 h of moderate showers – no problems noted. As my use of the SC92 system has been short term, I can’t comment on durability and battery life. If problems develop, I’ll report. Also worthy of mention: mounting magnets and conveniently located, soft-touch backlight control on receiver. And kudos to Smartro for not including date/time or other superfluous info on the sensor screen. The lack of clutter is greatly appreciated. On the downside, the numerals on the monitor that represent sensor number are very, very undersized. Since there’s a generous amount of free space in this region of the screen, I recommend that the sensor-number indicators be doubled or trebled in size. Also, the backlight is short lived (around 5 sec), and does not persist through a single cycle of sensor reports. Minor issues in an otherwise great product!

We have three of the Smartro SC42 temperature/humidity monitors that work very well, so we thought the SC92 might be a good indoor/outdoor monitor. We put all three SC42's and the SC92 (along with its remote sensor) in a closed room overnight. In the morning, the SC42's temperature readings were within 1 degree F, and the humidity readings were within 1 percent RH. The SC92 "indoor" reading was also close, however the SC92 remote sensor RH reading was off by 6%. Using the calibration feature, we corrected the remote RH reading. We then took one of the SC42's and the SC92 remote sensor outdoors (on a clear day in the shade). The SC42 readings quickly settled, but the SC92 remote had not settled after 3 hours (perhaps due to the small opening for sampling). So, the SC92 remote will tell you what the conditions were hours ago, but not the current conditions. Not very useful for a changing environment. Also, the display of the SC92 is difficult to read when it is below eye level - as it is when on a desk or table top, and the backlight is much brighter than it needs to be. So, although we like the SC42, we were disappointed with the SC92 and returned it.

I bought these units to replace a 20+ year old thermometer/hygrometer. The hygrometer no longer functioned. I had high hopes for the replacement. I also purchased an additional sensor. The main unit is located by my back door with the sensors located on my enclosed porch and under my gazebo. I bought these units because the remote sensors display data. If I’m in my backyard, I can check the temperature/ humidity without going inside my house. I installed batteries in each unit and let them sit side by side for an hour to adjust. None of the temperature or humidity readings matched. Temperature varied by 5 degrees, humidity by 7 percent. I compared the readings on the new units with 3 existing monitors. I have 2 ac units that regulate both temperature and humidity and a separate device I use in my humidor. These other units matched within a degree and 1% for humidity. The new units were not even close. I calibrated each unit multiple times without much success. I thought maybe they needed more time to adjust so I let them sit overnight. This morning, the remote sensors are much better. The temperatures on the remote units match and agree with my other devices. The humidity on one remote unit matches as well. The humidity for the other remote unit is 4% high. Not too bad. The main unit requires special handling. If you are holding the unit, the heat and moisture from your hand will affect the measurements. Also be sure you’re not sitting under an air conditioning or heat vent. I recalibrated this unit again this morning and it is reasonable close to other readings. Note the term “calibration” is not really accurate unless you have another device that is trustworthy. Without this, you are really just making all the readings match. Also note the calibration adjustments are not retained when the batteries are replaced in the main unit. Recalibration will likely be an annual event, assuming the batteries last that long. The directions state,”This unit has passed professional testing and calibration. No extra calibration is required before use.” Since the unit is shipped without batteries and calibration info is not retained when the batteries are removed, this would seem to be a false statement. I’m not sure how long the sensor located outside will last. There is no seal to keep moisture out. The adjustment buttons on the main unit are not robust. I had some difficulty in getting this unit in calibration mode and some times the adjustment buttons didn’t work. They required pushing multiple times to get them to respond. I considered returning these units. If I had not had better results this morning, I would have returned them. Knowing what I know now, I would not have bought them. I gave them 3 stars as they seem reasonable accurate after taking considerable time to calibrate. I have doubts to how long a sensor placed outside will last.

I like the product as it's easy to use and accurate. Best of all is their customer service. The touch button to turn on the backlight was not working on my unit. I sent a note to their support. They were very responsive and after a few exchanges for problem determination they sent me a new unit which arrived within 2 days. It's great when a company stands behind its products!

sono felice: precisa , semplice, completa.

le colis était ouvert et déballé dans la boite aux lettres.....

Only ordered 5 months ago and it's faulty . Can't get a answer from seller to replace the main unit .

It's excellent quality and simple to use it