SMARTRO SC92 Wireless Digital Hygrometer Indoor Outdoor Thermometer

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

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.

After adding batteries (2 AA and 2 AAA), I followed the instructions and the receiver and the transmitter sync'd up fairly quickly (about 20 seconds). You have the ability to have up to 3 transmitters (on 3 channels) and allow the receiver to toggle between them. This feature will not work unless the transmitters is already sync'd to specific channel. The receiver has a built in temp sensor as well as the transmitter. The idea is that the receiver would be inside and the transmitter outside so you get to see both temperatures (top temp is transmitter/bottom is receiver temp). I had the transmitter and receiver right next to each other in the same room for 10 minutes and they were consistently off by 1.5 degree. Both temperatures were off from the actual room temperature (taken using a laser thermometer by 2 degrees and 3.5 degrees respectively). The receiver will allow you to calibrate the device by moving the numbers manually within the actual range. I am using this device to monitor the temperature of my truck's canopy/bed while my dogs are back there. I wanted something that provides temperatures pretty close to real time. The transmitter sends a signal to the receiver every 1 minute 15 seconds (1:15). You can tell because the red LED light on the transmitter blinks every 1:15. However, it doesn't update the temperate/humidity until the third cycle. So you have to wait 3:45 to get the updated temperature from the transmitter. In the big scheme of things this may not be a big deal and it will probably improve battery life. The device is $25 so don't have the expectation that this is a high quality heavy duty item. It gets the job done, but will probably crack/break if dropped from six feet (2 meters). I plan to leave it in my car so I won't be surprised if the receiver's plastic warps, but we will see.

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!

Today I saw that the outdoor measurement was blank. I replace the batteries then used Rufus from my past order to get the instructions on how to sync the outdoor unit with the in home base. It didn't work. I then realized the battery terminals of the outdoor unit needed cleaning and used white vinegar and a Q-Tip to clean them, re-initiated sync and it's working again. Yay for a good product and good engineering. And for being able to look up your order and get helpful instructions.

Versatile, accurate and priced right. We moved in a new place with an in house humidifier but we felt the house was still too dry despite the highest humidity setting. The reading of this unit matched the service techs...it helped us diagnose we actually needed a larger home humidifier...the one at the house was under powered!

Okay, so I must have gotten the broken one because it is off by almost 20 degrees F. This one reads 10 degrees F while all my other thermometers show -7 degrees F. Glad I am good at maths so I can quickly make the China to US conversion. Very easy to read the numbers. Too bad they don't mean anything.

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.