Introduction
The Bresser External Thermo-Hygro Sensor is designed to accurately measure temperature and humidity. It can function as a standalone device or as an additional sensor for compatible Bresser weather stations, allowing you to monitor climate conditions in various areas of your home, such as living rooms, bedrooms, children's rooms, kitchens, or bathrooms.
This sensor transmits measurement data wirelessly up to a distance of 80 meters to your main weather station. It also features its own integrated LCD screen, enabling direct on-site verification of current values.

Figure 1: Front view of the Bresser External Thermo-Hygro Sensor, showing the LCD display with temperature (18.2°C) and humidity (46%) readings, and a channel indicator (CH1).
Product Features
- Accurate measurement of temperature and humidity.
- Clear LCD display for direct reading.
- Functions as a standalone thermo-hygrometer or as an additional sensor for compatible Bresser weather stations.
- Wireless transmission range up to 80 meters (open area).
- IP44 protection rating, making it splashproof and suitable for various environments.

Figure 2: The sensor is designed with IP44 water resistance, indicating it is protected against splashing water from any direction.
Package Contents
Upon opening the box, you will find:
- 1x Bresser Wireless Thermo-Hygro Sensor (Model: 7009985)
- 1x Instruction Manual
Note: 2 x 1.5V AAA batteries are required for operation and are not included in the package.
Setup
1. Battery Installation
- Locate the battery compartment on the back of the sensor.
- Slide open the battery compartment cover.
- Insert 2 x 1.5V AAA batteries, ensuring correct polarity (+ and -).
- Close the battery compartment cover securely.

Figure 3: Rear view of the sensor, illustrating the battery compartment and the channel selection switch.
2. Channel Selection
If using the sensor with a Bresser weather station, select the desired channel (1, 2, or 3) using the switch inside the battery compartment. Ensure this channel matches the channel selected on your main weather station for proper communication.
3. Placement
For optimal performance, place the sensor in a location that provides accurate readings for the area you wish to monitor. Avoid direct sunlight or extreme heat sources, which can affect temperature readings. The IP44 rating allows for outdoor placement, but avoid submerging the device in water.
Operating Instructions
Reading the Display
Once batteries are installed, the sensor will automatically begin measuring temperature and humidity. The current readings will be displayed on the LCD screen.

Figure 4: Side view of the sensor, highlighting the clear LCD display showing temperature and humidity.
- The large number indicates the temperature in degrees Celsius (°C).
- The smaller number below the temperature indicates the relative humidity in percentage (%).
- "CH1", "CH2", or "CH3" indicates the selected transmission channel.
Connecting to a Weather Station
If you are using this sensor as an additional unit for a compatible Bresser weather station, ensure the channel selected on the sensor matches the channel you wish to assign on your main station. Refer to your main weather station's manual for instructions on pairing additional sensors.
Maintenance
- Cleaning: Wipe the sensor with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- Battery Replacement: Replace batteries when the display becomes dim or readings become inconsistent. Always replace both batteries at the same time.
- Storage: If storing the device for an extended period, remove the batteries to prevent leakage.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No display or dim display. | Batteries are low or incorrectly installed. | Replace batteries with new 1.5V AAA batteries, ensuring correct polarity. |
| Sensor not transmitting data to weather station. | Incorrect channel selection; sensor out of range; interference. | Ensure sensor channel matches weather station channel. Move sensor closer to the weather station. Reduce sources of interference (e.g., other electronic devices). |
| Inaccurate readings. | Sensor placed in direct sunlight or near heat/cold sources. | Relocate the sensor to a shaded area or away from direct heat/cold sources for more accurate ambient readings. |
Specifications
- Model Number: 7009985
- Dimensions: 71 x 65 x 23 mm
- Weight: 44 grams
- Power Source: 2 x 1.5V AAA batteries (not included)
- Material: Plastic, Aluminum
- Display Type: LCD
- Wireless Range: Up to 80 meters (open area)
- Protection Rating: IP44 (splashproof)
- Global Trade Item Number (GTIN): 04007922080154
Compatible Bresser Weather Stations
This sensor (Model 7009985) is compatible with the following Bresser weather station models:
- 7000023
- 7007201
- 7004200
- 9604200
- 7007511
- 9600028
- 7000012CM3000
- 7000012GYE000
- 7000013
- 9070600
- 7007402
- 9070700
- 9604210
- 7004210
- 7006500
- 9604100
- 9070300
- 9070110
- 7007520
- 9070710
- 7000030
- 70076610
- 7000002
- 7000004
- 7000020QT5000
- 7000020CM3000
- 7000020GYE000
- 7001800QT5000
- 7001800CM3000
- 7001800GYE000
- 700755000CM3000
- 7007600QT5000
- 7000022CM3000
- 7007500
- 7007501
- 9080600
- 8020210GYE000
- 8020210CM3000
- 7004330
- 7004340
- 7006310
- 7004220
- 7000027
- 7000029
- 7000060
- 7004350
- 70043600
- 70004370
- 7004380
- 7006510
- 7007350
- 7007620
Warranty and Support
For warranty information and technical support, please refer to the official Bresser website or contact their customer service directly. Keep your purchase receipt as proof of purchase for any warranty claims.
For further assistance, you may visit the Bresser brand page on Amazon.







