Product Overview
The D'Addario Planet Waves Humidity & Temperature Sensor (HTS), Model PW-HTS, is a precision-designed device that digitally indicates accurate relative humidity levels and temperature. It is an essential tool for maintaining proper climatic conditions for musical instruments, particularly those made of wood, to prevent damage caused by extreme humidity fluctuations.
Key features include an accurate display of temperature and humidity, a memory function to track recent high and low levels, and a built-in clock and calendar. This sensor is designed to help users monitor the environment of their instruments, especially when stored in cases, ensuring their longevity and optimal performance.

The D'Addario Planet Waves Humidity & Temperature Sensor, shown in its retail packaging, highlights its key features: easy-to-use digital display, built-in memory function, and integrated digital clock and calendar.
Setup and Initial Use
The D'Addario Planet Waves HTS comes ready for use with an included AA battery. To begin monitoring, ensure the battery is correctly installed. The device is designed for tabletop placement or can be easily positioned within an instrument case.
Battery Installation
- Locate the battery compartment on the back of the unit.
- Open the compartment cover.
- Insert one AA battery, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
Upon successful battery installation, the digital display will activate, showing current humidity and temperature readings.

The front of the D'Addario Planet Waves Humidity & Temperature Sensor, displaying its digital screen with humidity and temperature readings, along with the 'set point', 'program', and 'memory' control buttons.
Operating Instructions
The HTS provides real-time data and historical records to help you maintain ideal conditions for your instrument.
Reading the Display
- Relative Humidity (RH): Displays the current percentage of humidity in the environment, ranging from under 20% to 99%.
- Temperature: Shows the current temperature in either Fahrenheit (°F) or Celsius (°C), ranging from -32°F to 122°F (-35°C to 50°C).
- Time and Date: The unit includes a built-in clock and calendar for tracking historical data.
Switching Temperature Units
Use the designated button (often labeled with °F/°C or similar) to toggle between Fahrenheit and Celsius temperature displays.
Memory Feature
The memory feature records the highest and lowest temperature and humidity levels the instrument has been exposed to, along with the date and time of these occurrences. Consult the device's buttons (e.g., 'memory' or 'min/max') to access this historical data.

A close-up of the sensor's digital display, showing a relative humidity reading of 38% and a temperature of 79°F, along with the current time and date.
This video provides a product overview, showing how the D'Addario Planet Waves Humidity & Temperature Sensor is placed and used within a guitar's soundhole to monitor environmental conditions.
Maintenance
Regular maintenance ensures the longevity and accuracy of your D'Addario Planet Waves HTS.
Battery Replacement
When the display dims or stops functioning, it is time to replace the AA battery. Follow the battery installation steps outlined in the 'Setup and Initial Use' section.
Cleaning
Wipe the unit with a soft, dry cloth to remove dust or smudges. Avoid using harsh chemicals or abrasive materials, as these can damage the display or casing.
Humidifier Maintenance (for companion products)
While the HTS monitors humidity, it does not humidify. For instruments requiring humidification, such as acoustic guitars, it is crucial to use a dedicated humidifier (e.g., D'Addario Humidipak) and maintain it according to its instructions. The HTS helps you know when your humidifier needs attention.
This video illustrates the D'Addario Humidipak system, explaining how to insert the packets into the saddle and headstock pouches to maintain optimal humidity levels for acoustic guitars.
Troubleshooting
If you encounter issues with your D'Addario Planet Waves HTS, consider the following:
- No Display or Dim Display: Check the battery. Ensure it is correctly installed and has sufficient charge. Replace if necessary.
- Inaccurate Readings: Ensure the sensor is placed in a stable environment away from direct heat sources, drafts, or extreme cold. Allow a few minutes for readings to stabilize after placement or significant environmental changes.
- Buttons Unresponsive: Try removing and reinserting the battery to reset the device.
Specifications
- Model Number: PW-HTS
- Product Dimensions: 4"W x 2.75"H
- Item Weight: 1.44 ounces
- Color: Black
- Battery: 1 AA battery (included)
- Operating Humidity: Under 20% to 99%
- Temperature Range: -32°F to 122°F (-35°C to 50°C)
- Temperature Accuracy: +/- 5%
- Mounting Type: Tabletop
Warranty and Support
For detailed warranty information and customer support, please refer to the product packaging or visit the official D'Addario website. Keep your purchase receipt for any warranty claims.





