INKBIRDPLUS PTH-9A
INKBIRDPLUS PTH-9A Indoor Air Quality Monitor User Manual
Model: PTH-9A
Introduction
The INKBIRDPLUS PTH-9A is a versatile 6-in-1 indoor air quality monitor designed to provide accurate readings of various environmental parameters. This device helps you understand and maintain a healthy indoor environment by detecting Carbon Dioxide (CO2), Particulate Matter (PM2.5 and PM10), Air Quality Index (AQI), Temperature, and Humidity. This manual provides essential information for the proper setup, operation, and maintenance of your device.

Figure 1: INKBIRDPLUS PTH-9A Multifunctional Air Detector overview, highlighting its 6 detection capabilities.
Product Overview
Key Features
- 6-in-1 Air Quality Monitoring: Accurately detects CO2 concentration, PM2.5, PM10, AQI, temperature, and humidity.
- Color LED Screen: Clear display with backlight shows all values at a glance, including time, date, and year.
- AQI Alarm Function: Features three stages of AQI (Normal, Warning, Danger) with an audible alarm when the AQI exceeds 100.
- Calibration Function: Allows for manual calibration of the carbon dioxide concentration value for enhanced accuracy.
- Temperature Unit Switching: Supports switching between Celsius (°C) and Fahrenheit (°F).
- Versatile Placement: Can be placed on a desktop or hung on a wall using the integrated hook design.
What's in the Box
- 1 x INKBIRDPLUS PTH-9A Indoor CO2 Detector
- 1 x Lithium Ion Battery (included)
- 1 x USB Charging Cable
- 1 x User Manual (this document)
Setup
Initial Charging
Before first use, fully charge the device using the provided USB cable. Connect the USB cable to the device's charging port and a standard USB power adapter (not included). The device is designed to operate while charging, and continuous power connection is recommended for optimal performance.

Figure 2: The device connected for USB charging.
Powering On/Off
To power on or off the device, press and hold the power button located on the top of the unit. The color LED screen will illuminate upon powering on.
Operation
Device Layout and Controls

Figure 3: Labeled components and controls of the INKBIRDPLUS PTH-9A.
The device features a clear display and three control buttons on the top panel:
- Power Button (Center):
- Long press: Power on/off.
- Press: Switch the display of time, date, and year.
- Double click: Enter setting mode.
- "DOWN" Button (Left, marked with '-'):
- Press: Turn backlight on/off.
- In setting mode: Decrease parameter value.
- "UP" Button (Right, marked with '+'):
- Press: Turn alarm sound on/off.
- In setting mode: Increase parameter value.

Figure 4: Detailed operating instructions for button functions and time/date setting.
Switching Temperature Units (°C/°F)
To switch between Celsius (°C) and Fahrenheit (°F), press the "DOWN" button (marked with '-') when the device is on and not in setting mode. The temperature display will change accordingly.

Figure 5: Temperature unit conversion between Celsius and Fahrenheit.
Calibration
CO2 Concentration Calibration
The device features a calibration function for the CO2 concentration value to ensure accuracy. This process should be performed in a well-ventilated area, away from people, to ensure accurate baseline readings.
- Ensure the device is powered off.
- Take the device to a well-ventilated outdoor area.
- Press and hold all three buttons (Power, DOWN, UP) simultaneously.
- The product will enter the automatic calibration state for 200 seconds. The screen will display a countdown.
- Once the calibration is complete, the device will return to normal operation.

Figure 6: Initiating the calibration function by pressing three buttons.

Figure 7: Visual representation of the calibration process.
AQI Alarm Function
The device provides visual and audible alerts based on the Air Quality Index (AQI) levels. The AQI is categorized into three stages:
- Normal Mode: AQI 0-50 (Green indicator)
- Warning Mode: AQI 51-100 (Yellow indicator)
- Danger Mode: AQI 101-500 (Red indicator)
When the AQI index exceeds 100 (Danger Mode), the device will emit an audible alarm. To stop the alarm sound, press the "UP" button (marked with '+').

Figure 8: Three stages of AQI concentration and their corresponding color indicators.

Figure 9: Stopping the AQI alarm by pressing the '+' button.
Time and Date Setting
To set the current time, date, and year on your device:
- Double-click the Power button (center button) to enter setting mode.
- The setting sequence is Year, Date, then Time.
- Use the "DOWN" (-) and "UP" (+) buttons to adjust the parameter value.
- Press the Power button to confirm the current item and move to the next setting item.
- After setting the time, press the Power button again to save and exit the setting mode.

Figure 10: Setting the time on the device display.
Placement and Application
The INKBIRDPLUS PTH-9A is suitable for monitoring air quality in various indoor environments. Its compact design allows for flexible placement.
Recommended Locations
- Bedrooms and Living Rooms
- Offices and Workspaces
- Kitchens and Cellars
- Grow Tents
- Vehicles
Mounting Options
The device can be placed on any flat surface, such as a desk or shelf. It also features a hook design on the back, allowing it to be conveniently hung on a wall for easy viewing.

Figure 11: Examples of suitable application environments for the air quality monitor.

Figure 12: Illustrating desktop and wall-mount placement options.
Maintenance
To ensure the longevity and accurate performance of your INKBIRDPLUS PTH-9A, follow these maintenance guidelines:
- Cleaning: Gently wipe the device with a soft, dry cloth. Do not use abrasive cleaners, solvents, or immerse the device in water.
- Sensor Care: Avoid blocking the air inlets/outlets on the device, as this can affect sensor accuracy. Keep the device away from dust, lint, and strong chemical fumes.
- Storage: When not in use for extended periods, store the device in a cool, dry place.
- Battery: The device contains a built-in Lithium Ion battery. If the device is not used for a long time, it is recommended to charge it periodically to maintain battery health.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Low battery or no power. | Connect the device to a USB power source and allow it to charge. Ensure the power button is pressed and held to power on. |
| Inaccurate CO2 readings. | Device requires calibration. | Perform CO2 calibration in a well-ventilated outdoor area as described in the "Calibration" section. |
| AQI alarm sounds frequently. | High AQI detected or alarm is sensitive. | Check the AQI reading and ventilate the area if necessary. Press the "UP" (+) button to temporarily silence the alarm. |
| Backlight is not bright enough or not working. | Backlight setting or potential malfunction. | Press the "DOWN" (-) button to toggle the backlight. If the issue persists, contact customer support. |
| Temperature/Humidity readings are inconsistent. | Environmental factors or sensor variation. | Ensure the device is placed in a stable environment away from direct heat sources, vents, or extreme humidity changes. Allow time for readings to stabilize. If readings remain erratic, contact customer support. |
Specifications
| Parameter | Value |
|---|---|
| Brand | INKBIRDPLUS |
| Model | PTH-9A Indoor Air Quality Monitor |
| Product Dimensions | 4D x 8.9W x 9.9H Centimeters |
| Item Weight | 304 g |
| Power Source | Battery Operated (Lithium Ion) |
| Battery Type | 1 Lithium Ion battery (included) |
| Sensor Type | Electrochemical |
| Operating Humidity | Up to 95 percent |
| Alarm | Audible |
| Color | Black |
| Country of Origin | China |
Warranty and Support
INKBIRDPLUS products purchased directly from official INKBIRD stores are eligible for official after-sales service. For warranty claims, technical assistance, or any product-related inquiries, please contact INKBIRDPLUS customer support through their official channels or the retailer where the product was purchased.
Please refer to your purchase documentation for specific warranty terms and conditions.
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