1. Introduction
The Testo 420 Balometer Kit is designed for precise measurement of airflow in large air supplies, returns, and swirl outlets. It provides reliable data for air velocity, volume flow, absolute and differential pressure, air temperature, and relative humidity. This manual provides essential information for the correct setup, operation, and maintenance of your device.
Figure 1: The Testo 420 Balometer Kit, fully assembled with the control unit visible at the base.
2. Setup
- Unpacking: Carefully remove all components from the packaging. Verify that all items listed in the delivery scope are present: Testo 420 airflow capture hood control unit, USB cable, batteries, flow straightener, and soft-shell protective case.
- Battery Installation: Open the battery compartment on the control unit and insert the 4 AA batteries provided, ensuring correct polarity.
- Control Unit Attachment: Securely attach the control unit to the base of the airflow capture hood. Ensure it clicks into place.
- Flow Straightener Installation: Insert the flow straightener into the hood's base. This component is crucial for converting turbulent air into a uniform flow, ensuring accurate measurements.
- Hood Assembly: Extend the fabric hood and attach it to the frame. Ensure it is taut and properly secured to prevent air leakage during measurements.
Figure 2: Bottom view of the Testo 420 Balometer, showing the integrated flow straightener designed to ensure accurate airflow readings.
3. Operating Instructions
3.1 Powering On and Initial Calibration
- Press the power button on the control unit to turn on the device.
- Allow the device to perform its automatic zeroing process. This ensures higher accuracy for low-pressure measurements.
3.2 Taking Measurements
The Testo 420 measures various parameters including air velocity, volume flow, absolute and differential pressure, air temperature, and relative humidity.
- Position the balometer hood over the air outlet or inlet to be measured. Ensure a complete seal around the opening to prevent air leakage.
- Read the measurements directly from the control unit's display. The display is tiltable for ergonomic viewing, especially during overhead measurements.
- For measurements in ducts, the removable control unit can be combined with an optional pitot tube and connection hose (sold separately).
Figure 3: A technician using the Testo 420 Balometer to measure airflow from a ceiling vent, demonstrating its application for large air supplies.
3.3 Bluetooth Connectivity and App Usage
The Testo 420 features Bluetooth connectivity for remote monitoring and documentation via the MeasureQuick App.
- Download the MeasureQuick App on your smartphone or tablet.
- Enable Bluetooth on your mobile device and the Testo 420 control unit.
- Pair the devices following the app's instructions.
- Monitor all measurements remotely and send results directly from the job site for convenient documentation.
Figure 4: The Testo 420 Balometer in operation, with a user monitoring real-time data on a smartphone via the MeasureQuick App.
4. Maintenance
4.1 Cleaning
- Wipe the exterior of the control unit and hood with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- Ensure the flow straightener is free from dust and debris. Clean gently if necessary.
4.2 Battery Replacement
Replace batteries when the low battery indicator appears on the display. Use only specified AA batteries.
4.3 Storage
When not in use, store the Testo 420 Balometer Kit in its soft-shell protective case in a dry, dust-free environment. Remove batteries if storing for extended periods.
Figure 5: The Testo 420 Balometer Kit packed in its soft-shell protective case, highlighting its portability and ease of storage.
5. Troubleshooting
- Device not powering on: Check battery installation and charge level. Replace batteries if necessary.
- Inaccurate readings: Ensure the hood forms a complete seal around the air outlet. Verify the flow straightener is correctly installed and clean. Allow for automatic zeroing before measurement.
- Bluetooth connection issues: Ensure Bluetooth is enabled on both the control unit and your mobile device. Restart both devices and try pairing again.
- App not displaying data: Check if the app is updated to the latest version. Ensure the device is properly paired and within Bluetooth range.
6. Specifications
| Parameter | Measuring Range | Accuracy |
|---|---|---|
| Temperature | -4° to 158 °F / -20 to +70 °C | ±1 °F (32° to 158 °F) / ±0.5 °C (0 to +70 °C) / ±1.4 °F (-4° to 32 °F) / ±0.8 °C (-20 to +0 °C) |
| Humidity | 0 to 100 %rH | ±1.8 %rH + 3 % of mv at +77 °F / ±1.8 %RH + 3 % of mv at +25 °C (5 to 80 %rH) |
| Differential Pressure | -0.480 to 0.480 InH2O / -120 to +120 Pa | ±2 % of mv + 0.002 InH2O at +72 °F, 405 InH2O / ±2 % of mv + 0.5 Pa at +22 °C, 1013 hPa |
| Absolute Pressure | 280 to 440 InH2O / 700 to 1100 hPa | ±1 InH2O / ±3 hPa |
| Volume Flow | 24 to 2354 CFM / 40 to 4000 m3/h | ±3 % of mv + 7 CFM at +72 °F / ±3 % of mv + 12 m3h at +22 °C; 405 InH2O (50 to 2060 CFM) / 1013 hPa (85 to 3500 m3/h) |
| Dimensions (Standard hood) | 24 x 24 in. / 610 x 610 mm | |
| Weight | 102 oz. / 2900 g | |
| Battery Life | 40 hours | |
| Item Model Number | 0563 4200 | |
| Batteries | 4 AA batteries required (included) | |
| Material | Nylon | |
7. Warranty Information
For detailed warranty information regarding your Testo 420 Balometer Kit, please refer to the documentation provided with your purchase or visit the official Testo website. Warranty terms and conditions may vary by region.
8. Support
If you require technical assistance, have questions about your Testo 420 Balometer Kit, or need to order replacement parts, please contact Testo customer support. Contact information can typically be found on the Testo official website or in the product packaging.
You can also visit the Testo Store on Amazon for additional product information and accessories.
