Extech
Handheld test & measurement instruments — humidity, temperature, water quality, power, and more
Extech Humidity Meters
36 products across 28 product families
2 models445580 Humidity/Temp Pen
Click to compare & select →
2 models445715 Hygro-Thermometer with Remote Sensor
Click to compare & select →
2 models445815 Humidity Alert
Click to compare & select →
2 modelsRH200W Multi-Channel Wireless Hygro-Thermometer
Click to compare & select →
2 modelsRH300 Psychrometer
Click to compare & select →
2 modelsRH350 Psychrometer
Click to compare & select →
2 modelsRH390 Psychrometer/Precision
Click to compare & select →
2 modelsSD500 Humidity/Temperature Datalogger
Click to compare & select →
42280A Temperature and Humidity Datalogger
The Extech 42280A is designed to continuously monitor temperature and humidity so you can maintain ideal storage conditions in laboratories and cleanrooms while ensuring comfort in hospitals and other indoor working facilities. This datalogger with max/min mode records up to 24,000 data sets including date and time stamp and features both audible and visible alarms. You can generate PDF reports that show trending graphs, or export data to a Microsoft Excel spreadsheet, making it easy to identify irregularities in temperamental environments.
44550 Humidity/Temp Pen
The Extech 44550 is a pen style humidity and temperature meter. It features a dual LCD for simultaneous display of relative humidity and temperature (°C/°F switchable). This temperature pen measures humidity from 20% RH to 90% RH ± 5% RH and temperature from -10°C to 50°C ± 1°C (14°F to 122°F ± 2°F). It is pocket sized for quick and reliable measurements at any location. The max/min memory functions for display of highest and lowest readings for both measurements. Complete with pocket clip and one LR44 button battery.
445702 Indicator, RH/Temp w/Clock
The Extech 445702 combines 3 displays for time, temperature and humidity. The clock displays both 12 and 24 hour time. Includes a maximum/minimum with reset function. Humidity measures 10% RH to 85% RH ± 6% RH, and temperature measures -10°C to 60°C ± 1°C (14°F to 140°F ± 1.8°F). Complete with built-in tilt stand, wall mounting bracket, and AAA battery.
445703 Indicator, RH/Temp Big Digit
This Big Digit Hygro-Thermometer has 1 in. digits on a super large LCD. It simultaneously displays humidity from 10 to 99% and temperature from 14 to 140°F or -10 to 60°C. Accuracy is ±5%RH and ±1.8°F/±1°C. Maximum/minimum with reset function. Complete with stand, wall mounting bracket and 1 AAA battery.
445713 RH Indicator, Big Digit Indoor/Outdoor
The Extech Big Digit Hygro-Thermometer simultaneously displays indoor and outdoor temperature and humidity. It measures humidity from 10% RH to 99% RH ± 5% RH and temperature from -10°C to 60°C ± 1°C (14°F to 140°F ± 1.8°F). A max/min with reset function stores and recalls high and low measurements for all 4 parameters. Complete with built-in stand, wall mounting bracket, outdoor sensor with 89 cm (35 in) cable, and 1.5 V AAA battery.
445814 Humidity Alert, Big Digit RH, Temp, Dew Point
The Extech 445814 Humidity Alert Hygro-Thermometer has a programmable % RH audible and visual alarm that alerts you when humidity exceeds the set limit. A large LCD simultaneously displays temperature, humidity, and dew point. This product measures humidity from 10% RH to 99% RH ± 4% RH and temperature from -10°C to 60°C ± 1°C (14°F to 140°F ± 1.8°F). Rear calibration pot for humidity and temperature. Featuring maximum/minimum with reset functions that store and recall the highest and lowest readings recorded. Comes complete with built-in stand, wall bracket and one AAA battery.
CO270 Indoor Air Quality Meter with Temp, Humidity, Dew Point and CO2 Levels
The Extech CO270 air quality meter delivers precise CO₂, humidity, dewpoint, and temperature readings—all powered by just three × AAA batteries for up to a year. With a large, easy-to-read display, graphical air quality indicators, and anti-theft features, it’s perfect for manufacturing sites, warehouses, schools, offices and healthcare facilities.
CTH10A Clock, Radio Controlled, Temp/Humidity
The CTH10A is an attractive wall clock features an oversized 109 mm (4.3 in) digit time display that can be easily view from a longer distance than regular sized clocks. It receives Time Code from NIST Radio Station WWVB and it automatically adjusts year, date, day, hour, minute, second, and Daylight Savings Time. In addition, it also measures Temperature and Relative Humidity! Perfect for desktop or wall mount display. This clock meter also features automatic adjust for daylight savings time (DST), programmable alarm clock with snooze feature, and a built-in stand for desktop or wall-mount. Complete with built-in stand and three C size batteries
RH101 Hygro-Thermometer with IR Thermometer
This Combination Humidity meter plus Infrared Thermometer features a large backlit LCD with Primary and Secondary displays. Primary display is user selectable for IR or Humidity; Secondary always displays ambient temperature. Infrared thermometer has built-in laser pointer and an 8:1 distance to target ratio. Data Hold and MAX, Auto power off. Complete with 9V battery and carrying case.
RH250W Hygro-Thermometer with Connectivity to Exview App
The Extech RH250W is a compact Hygro-Thermometer with Bluetooth connectivity, which allows building and maintenance professionals to view and share relative humidity and temperature data directly from a mobile device using the free ExView app. With the capability to capture data, display trends, set visual and audio alarms, and send reports, users can gain deeper insights on equipment and building health.
RH490 Psychrometer, Precision
Anyone whose job relies on calculating humidity levels will appreciate the Extech Hygro-Psychrometer. In addition to measuring relative humidity in 30 seconds, this handheld instrument captures dew point, wet bulb, temperature and water vapor levels (Grams per Kilogram and Grains per Pound). This utility tool will store maximum and minimum readings until the memory is cleared and includes a data-hold button for rapidly fluctuating measurements. Complete with carrying case and 9V battery.
RH550 Graphical Humidity/Temperature Chart Recorder with Touch-Screen
Simultaneously datalog and monitor relative humidity, temperature, and calculated dew point on the Extech RH550. It features live or user-scheduled recording time and programmable Min/Max alarm set points. A built-in stand is included for desktop use, as well as a bracket for wall-mounting. The RH550 also features a field-replaceable probe that can be attached to the monitor or on a 6.5 ft (2 m) cable. This recorder is useful in office buildings, conference rooms, labs, hospitals, cleanrooms, greenhouses, food storage facilities, and more.
RH600 Handheld Dewpoint Meter
The RH600 accurately measures and datalogs dew point levels in compressed air systems. This high-precision meter can help manufacturing professionals protect product quality while avoiding damaged pneumatic equipment, corrosion, and problems in cylinder and valve systems. Featuring a color graphical display, the RH600 provides clear, stable readings, allowing you to measure dew point temperature down to -50°C (-58°F) in max ambient pressure of 20 bar. Set high/low audible and visible alarms for temperature, relative humidity, and dew point thresholds. You can also easily log and transfer recorded data to a PC in CSV format to create inspection reports fast.
RHT10 Humidity & Temperature Datalogger/USB
The RHT10 datalogs Humidity and Temperature readings (up to 16,000 each) with user programmable sample rates from 2 seconds up to 24 hours for days, weeks and months. USB interface for easy setup and download. Dew Point indication via the included Windows software. User-programmable High/Low alarm thresholds for RH and temperature. Complete with 3.6-Volt Lithium battery, protective USB cap, mounting bracket, and Windows compatible software for analysis.
RHT20 Humidity & Temperature Datalogger w/LCD
The RHT20 is a Humidity Temperature Datalogger which records up to 16,000 Humidity and 16,000 Temperature readings with a user programmable sample rate. USB interface for easy setup and data download. Selectable data sampling rates from 1s to 24hr. User-programmable alarm thresholds for RH and Temperature. LCD displays current temperature and humidity readings plus Min/Max and Alarm status. Long battery life. Place or mount the datalogger in monitoring location (storage bin, truck, cargo hold, freezer, temperature-controlled room, etc.). Datalogger records temperature and humidity at sample rate set by user. Connect the datalogger to your PC via the USB interface to retrieve readings. Datalogger displays the current Humidity and Temperature plus Min/Max and alarm status so it can viewed anytime during the recording process. Complete with battery, mounting bracket, and software.
RHT30 Humidity & Temperature Datalogger with USB
The datalogger is designed with a rugged housing and a standard USB connector where stored readings (up to 48,000 data) are conveniently transferred to a PC in PDF or Excel spreadsheet format when plugged in. Additional features include an 8-location logger bookmark, 6-language options, programmable sampling interval, adjustable alarm, and password-protected security log-in. Large LCD optimizes viewing and the smart LED provides color-coded humidity, and temperature reading status.
SD700 Pressure/Humidity/Temp Datalogger
SD700 records data to SD card in Excel format. Displays Barometric Pressure in 3 units of measure: hPa, mmHg, and inHg. Triple LCD simultaneously displays Barometric Pressure, Temperature, and Relative Humidity. Datalogger date/time stamps and stores readings on an SD card in Excel format for easy transfer to a PC. Selectable data sampling rate from 5, 10, 30, 60, 120, 300,600 seconds. Complete with (6) AAA batteries, SD memory card, Universal AC adapter, and mounting bracket.
SD800 CO2/Humidity/Temperature Datalogger
SD800 monitors air quality in schools, office buildings, greenhouses, hospitals and anywhere that high levels of carbon dioxide are generated. Selectable data sampling rate of 5, 10, 30, 60, 120, 300,600 seconds or automatic. Maintenance free dual wavelength NDIR (non-dispersive infrared) CO2 sensor. Triple LCD simultaneously displays CO2, Temperature and Relative Humidity. Complete with six AAA batteries, 2G SD memory card, universal AC adaptor, and mounting bracket.
SDL500 Hygro-Thermometer SD Logger
The SDL500 records data on an SD card in Excel format. Relative Humidity, Temperature, Dew Point, and Wet Bulb measurements. Adjustable data sampling rate. Stores 99 readings manually and 20M readings via 2G SD card. Type K/J Thermocouple input for high temperature measurements. Large backlit dual LCD display. Record/Recall Min, Max, Data Hold and Auto power off functions. Complete with 6 x AA batteries, SD card, carrying case and Humidity/Temperature probe.
Accessories & Parts
Need Help With Extech Products?
Our team is factory-trained and ready to help you select, configure, and maintain Extech instruments.
Get Expert Help