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Testo

Testo 605i Thermohygrometer - Hygrometer & Indoor Thermometer for Humidity Measurement and Indoor Temperature - 90° Bendable In-Duct Temperature and Humidity Monitor with Bluetooth - iOS & Android

  • Based on 377 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, Sep 8
Order within 13 hours and 46 minutes
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Features

  • Efficient; The testo 605i thermohygrometer is ideal for measurements in rooms, ducts, crawl spaces, registers and environmental boxes and chambers due to the compact probe head bendable to 90
  • Smart; Enabling live data feed integration and automatic calculations which are conveniently displayed on your terminal device, the 605i temperature and humidity monitor is ideal for all HVAC/R technicians
  • Versatile; The testo 605i hygrometer and indoor thermometer measures relative air humidity and temperature in rooms and ducts and calculates dew point and wet bulb temperature automatically
  • Easy to use; The 605i digital humidity meter and indoor thermometer for home allows accurate remote monitoring and is operated via mobile device. Supplied calibrated and with 3 AAA batteries for instant use
  • App for Android and iOS; The free testo Smart Probes App is a powerful tool that allows you to read and log measurements of the thermometer and humidity gauge and create custom reports which can be saved and shared

Description

Testo 605i smart thermohygrometer - 90° bendable temperature and humidity monitor for in-duct measurementsThe testo 605i humidity gauge and indoor thermometer for home is an efficient, easy-to-use tool for temperature and humidity measurement in rooms, ducts, crawl spaces, registers and environmental boxes/chambers. The hygrometer and indoor thermometer supports Bluetooth, making it easier than ever to create reports and generate automatic calculations such as calculations of dew point and wet bulb temperature.Technical data 605i:Measuring range: -4° to 140 °F / -20 to +60°CAccuracy: ±1.4 °F (-4° to 32 °F) / ±0.8 °C (-20 to 0 °C); ±0.9 °F (32° to 140 °F) / ±0.5 °C (0 to +60 °C)Storage temperature: -4° to 140 °F / -20 to +60 °CResolution: 0.1 %rHBattery life: 150hBattery type: 3 x AAAWeight: 3.05 oz. / 86.4 gDimensions: 10 x 1 x 1 in. / 243 x 30 x 24 mmSystem requirements: requires iOS 8.3 or newer; requires Android 4.3 or newer; requires mobile end device with Bluetooth 4.0Scope of Delivery:1 x testo 605i Bluetooth thermo- hygrometer with app, 3 x AAA batteries, certificate of calibration

Color: black/orange


Brand: Testo


Product Dimensions: 1"W x 10"H


Item Weight: 95 g


Battery Description: Alkaline


Battery Description: Alkaline


Mounting Type: Tabletop


Operating Humidity: 10-35%, 35-65%, 65-90%, <10% RH or >90% RH (at 77°F)


Upper Temperature Range: 140 °F


Voltage: 3 volts


Temperature Accuracy: 0.5 °C


Temperature Reading Accuracy: plus_minus_0_point_5_degrees_celsius


Item Dimensions W x H: 1"W x 10"H


Item Weight: 95 g


Color: black/orange


Brand Name: Testo


Number of Items: 1


Manufacturer: Testo


Unit Count: 1 Count


Number of Packs: 1


Global Trade Identification Number: 31


Included Components: industrial-and-scientific-temperature-indicators


Model: 0560 2605 03


Part Number: 0560 2605 03


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Sep 8

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • Very good instrument
Style: Thermohygrometer
Best in class Use this thermohygrometer in many commissioning tests. Aside of a high accuracy, the online data capture and basic reports that can be exported in ccv format, makes this instrument a good option for field testing.
Reviewed in the United States on February 15, 2026 by L.Lopez
    • Wow thermostats are inaccurate!!!
Style: Thermohygrometer
I purchased this highly rated Testo 605i thermohygrometer to add to my arsenal of HVAC tools. This device measures both temperature and humidity very accurately. Even better it allows for a bluetooth connection to your phone and the Testo Smart app to trend both of these measurements. I just go to the Climate/Air Velocity section and select the Basic View at the top of the screen to see these. One of the issues I was having was what appeared to be poor dehumidification with our AC system. This turned out to be inaccurate because our Ecobee thermostats are incredibly inaccurate. In fact, one of them was off by 10% humidity and we thought we were going to have a mold problem because we could not get below 60%. This is outragous as we have struggled with this issue for a long time. In any case, I did several tests of this probe including with humidity packets in a ziplock bag and this thing was absolutely faithful in measuring humidity accurately. I was able to use the temperature and humidity correction (under settings, advanced options, thresholds and scroll to the bottom) within the Ecobee to get it dialed in correctly. I had to do this on 4 other Ecobee thermostats and based upon reading other comments/reviews on the Internet this is a known problem with these thermostats even when sealing the thermostat wiring hole. Sadly, our Airthings Plus is also reading too high humidity by about 8% but it does not provide any way to correct the reading. I'll have to use the Ecobees as our Hubitat home automation reference going forward as we have been using it to control a whole-house dehumidifier. Although this was a bit pricey and I didn't have time to shop around for a deal this was a fantastic tool to have in the tool box and can highly recommend it. It may end up saving you $$$ in the long run before having to invest in equipment to solve a problem that isn't necessary for dehumidification. 5/5 stars. ... show more
Reviewed in the United States on May 31, 2026 by AW2222
    • Very useful
Style: Thermohygrometer
Bought (3) nice for checking return, supply and ambient temps, works great with MeasureQuick app.
Reviewed in the United States on April 22, 2025 by Michael Cofske
    • Best bluetooth thermometer
Style: Thermohygrometer
Awesome to have something to check temps in a RIC
Reviewed in the United States on December 29, 2025 by Adam P.
    • Works great and connectivity it’s seamless
Style: Thermohygrometer
Turn on and throw it inside of a refrigerator you’re temping down and checking cut in cut out temps on and don’t have to worry about opening the door to check on it just download the app and see everything on your phone. Bluetooth distance is further then I thought it’d go. Also batteries last pretty long as well ... show more
Reviewed in the United States on September 4, 2023 by Randall Adams
    • no english instructions good customer service
Style: Thermohygrometer
as of now, can not get it to work. All directions are in Chinese. Update, customer service was excellent and steered me in the right direction. More of a learning curve for using the app, the instrument itself feels like its very good quality
Reviewed in the United States on April 23, 2025 by Amazon Customer
    • Testo 605i
Style: Thermohygrometer
Excelente Producto!.
Reviewed in the United States on December 13, 2025 by martin gabriel
    • Accuracy seems to be great
Style: Thermohygrometer
I wanted something I could use as an easy humidity standard. This unit had the best specs for the price. I bought it despite the drawback that it had no visible meter and needed a smartphone to display the readings. Turns out the smartphone requirement was its best feature. It will display a real time graph of the temperature and humidity readings. You can use the graph to see when it stabilizes, plus it will show you the fluctuations in the humidity and temperature. Since I'm using it for a humidity standard, couldn't calibrate that. I did calibrate the temperature readings against a lab thermometer. They exceeded the claimed accuracy. The difference between the readings of this instrument and the lab thermometer were essentially nil. ... show more
Reviewed in the United States on August 9, 2023 by R

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