BTMETER BT-100APP Anemometer w/Wireless Bluetooth, Digital Handheld Wind Speed Meter for Wind Chill, Air Velocity, Temperature, Vane Anemometer Gauge

It works great for testing blower motors.

Light weight, handy and shows the speed as it happens. Will show max or min. And hold or as it happens. Fun for the weather buff or for weather as it happens. Would be quite usable on a fire scene for winds conditions as they happen.

Ok

I'm pretty impressed. Chinese electronics of course, but seems well-designed. Working on Hot Rod cooling system with electric fan and tight engine compartment. Used the bluetooth function to monitor flows where I couldn't see display. Note you should not allow this instrument to heat up to normal underhood temperatures. Check all flows possible with engine off and electric fan on. Sitting still, most of my flow is going out the rear of a 7" tall hood scoop. I am interested in finding out if flow changes while driving sure to pressure at base of windshield. But If you have to drive and place the meter in a potentially hot area, do it quickly so you don't cook the meter case or electronics. Air going into front of radiator should always be OK to check, even with engine hot. Air out of a hot radiator is a no go. Just be careful with temperature of the meter. I did accidentally drop it 2' onto my cement driveway and it still works just fine. Remember that velocity in ft/min x area in feet = CFM So ft/min is the setting that I use the most - also seems the most accurate by giving highest value in display. If you check output of the fan (do cold) don't forget to subtract the area of the fan center when doing the calculation, and average the flow at outer part of blades vs inner part of blades.

I just got the BT-100-APP and did a test drive. I got this just for measuring my HVAC fan blower output at different vents as I have a variable speed blower. I believe for that purpose the device appears to work although I do not have a way to compare its accuracy for air flow. I can say for a fact that the temperature is off by 3 deg F which is a lot. Also the app is almost useless. The data tab gets it information from the device (not saved in the app) and it does this real slow - I could not wait for more than 2 minutes to see the latest data that I captured. The average button seems to only work for temperature and not for air flow - this is the most disappointing for me. There is no USB slot on the device so the included cable is useless. Other than all that, I just want to measure air flow, so that sort of meets my immediate need and can do without any bells and whistles. Even if that is not accurate, I can live with relative air flow measurements between the HVAC vents which will give me an idea of how each room is impacted. Overall this works for my need but hoping they can update the app to save data and provide some time frames to display the latest readings than have to scroll all the way down - even if that were possible with the slow display performance.

Bought this for shooting even though the stated Bluetooth range was 10 meters (33 feet). Bluetooth Class 2 is 2.5mW and conservatively rated at 33 feet. For my testing I paired to a Samsung Galaxy Tab A (SM-T280) tablet. It was a clear sunny morning, light wind, and away from any electrical noise sources. I set the anemometer up perpendicular to my shooting direction, near the target. You need to know the cross wind component to compensate for wind drift. Obviously I had a clear line of sight and started walking toward my shooting bench. After several trials, I always stayed connected at 150 feet (50 yards) and always dropped connection by 225 feet (75 yards). Each time I dropped connection I had to go back to the anemometer and power cycle it to re-establish the connection. The stated accuracy of +/- 5% is good enough for what I am doing, but I don't have a way of checking it. It would have been nice to display plus or minus for the air flow. There is an arrow on the top of the anemometer, I guess showing the direction of intended air flow, so you can read the display. In changing winds, you could end up compensating the wrong direction. For shooting, a ribbon will need to be near the anemometer to verify right or left wind bias. The vane spins opposite directions based on which side the air flows. I set up a fan to see if the anemometer would read the same regardless of air flow direction. Best I could tell, it does. The manual is OK, you can figure it out. A little more detail and a writer with more understanding of the English language would help. Overall, this is going to work great for my application.