Testo 420 · Flow Hood

2 Safety and the environment

2.1. About this document

Use

• Please read this documentation through carefully and familiarize yourself with the product before putting it to use. Pay particular attention to the safety instructions and warning advice in order to prevent injuries and damage to the products.
• Keep this document to hand so that you can refer to it when necessary.
• Hand this documentation on to any subsequent users of the product.

Symbols and writing standards

2.2. Ensure safety

• Do not operate the instrument if there are signs of damage at the housing, mains unit or feed lines.
• Do not perform contact measurements on non-insulated, live parts.
• Do not store the product together with solvents. Do not use any desiccants.
• Carry out only the maintenance and repair work on this instrument that is described in the documentation. Follow the prescribed steps exactly. Use only original spare parts from Testo.
• Dangers may also arise from the systems being measured or the measuring environment: Note the safety regulations valid in your area when performing the measurements.

2.3. Protecting the environment

• Dispose of faulty rechargeable batteries/spent batteries in accordance with the valid legal specifications.
• At the end of its useful life, send the product to the separate collection for electric and electronic devices (observe local regulations) or return the product to Testo for disposal.

3 Specifications

The testo 420 is used for volume flow measurements (main application), Pitot tube measurements and pressure measurements for air conditioning and ventilation systems. Thanks to its interchangeable flow hoods, the testo 420 can be used for air inlets and outlets of various sizes.

The testo 420 can be connected to the additional testo Smart App (Android/iOS) or the testo 400 via Bluetooth. This allows the readings to be conveniently displayed on a tablet/smartphone or the testo 400. Moreover, a measurement can be configured, started, stopped and saved via the app/the testo 400.

4 Technical data

The use of the wireless module is subject to the regulations and stipulations of the respective country of use, and the module may only be used in countries for which a country certification has been granted. The user and every owner has the obligation to adhere to these regulations and prerequisites for use, and acknowledges that the re-sale, export, import etc. in particular in countries without wireless permits, is his responsibility.

5 Product description

5.1. Overview

5.1.1. Measurement setup

A diagram shows the testo 420 flow hood setup:

• 1. Volume flow hood (standard hood 610x610 mm)
• 2. Actuator for manual measurement
• 3. Measuring instrument testo 420
• 4. Measurement base with differential pressure cross
• 5. Integrated flow straightener

5.1.2. Overview of testo 420

An image shows the testo 420 instrument with numbered parts:

• 1. Battery compartment, on rear of the instrument
• 2. Display
• 3. Control keys
• 4. Probe socket Mini-DIN (only for use on the measurement base)
• 5. Micro-USB port
• 6. Connection for pressure measurement

Instrument status icons:

Control keys

6 First steps

Inserting batteries/rechargeable batteries

1. Open the battery compartment.
2. Insert the batteries or rechargeable batteries (scope of delivery includes 4x 1.5V Type AA/LR6).
3. Close the battery compartment.

ℹ️ When not in use for a long period of time, take the batteries/rechargeable batteries out.

Implementing settings

1. Press [Menu] to access the menu.
2. Select the menu item you require using [Up], [Down], [Left], [Right].

Key functions

Settings menu structure

² Maximum of 15 minutes, measuring cycle 1 second
³ Maximum of 25 points and 1 minute per point.

7 Using the product

7.1. Switching Bluetooth® on and off

ℹ️ To establish a connection via Bluetooth, you need the testo 400 (App version 14.31 or later) or a tablet/smartphone with the testo Smart App already installed on it.

The app is available for iOS devices in the App Store or for Android devices in the Play Store.

Information about compatibility can be found in the relevant App Store.

ℹ️ Measurements can be configured and carried out using the testo 400 or the app and saved in the testo 420 instrument memory or directly on the testo 400 or the testo Smart App. During Bluetooth connection to your testo 400/mobile device, the measuring mode and memory function are not available on the testo 420.

Switching on Bluetooth

1. Hold [Power] down for 3 seconds.
2. Once the Bluetooth icon ? is shown on the display, Bluetooth is switched on.
3. If no connection is established, Bluetooth switches off after 10 mins.

or

1. Press [Menu] -> Instrument settings -> Bluetooth, press [Up] and [Down] to select -> On. Confirm with [Confirm].
2. Once the Bluetooth icon ? is shown on the display, Bluetooth is switched on.
3. If no connection is established, Bluetooth switches off after 10 mins.

7.2. Settings for the measurement

ℹ️ The sensor must not be exposed to volatile chemicals such as solvents (e.g. ketene, ethanol, isopropyl alcohol, toluene) or organic compounds, especially in high concentrations and corresponding gases, over a prolonged period of time.

7.2.1. Damping (Gliding Average)

If the readings fluctuate widely, it is advisable to damp the readings. The time range for the damping can be set manually between 5-20 seconds.

1. Press [Menu], then select Device settings and Gliding average.
2. The damping can be set between 5-20 seconds.

7.2.2. Hood Calibration

This input is provided for the filing of calibration data by the relevant calibration laboratory. The flow hood-specific adjustment data can be input manually for supply air and exhaust air and has a direct effect on the measurement results. Input option of 0.001-9.999.

1. Press [Menu], then select Device settings and Hood adjustment.
2. Calibration of the hood can be set for supply air and exhaust air.

7.2.3. Zeroing Interval (Automatic Zeroing)

The pressure sensor carries out automatic zeroing at regular intervals. These intervals can be set via the automatic zeroing.

1. Press [Menu], then select Device settings and Zeroing int.
2. The zeroing interval can be set between 1-20 seconds.

7.3. Volume flow measurement setup

Standard hood (610x610 mm, scope of delivery; 360x360 mm, accessories)

Diagrams illustrate the setup:

1. Pull the lower end of the hood over the measurement base.
2. Attach the hood at two corners using the snap fasteners.
3. Tighten the closure.
4. Screw together a short and long section of the support rods (4x) at the silver ends.
5. Push the support rods (4x) through the hood, along the markings and into the funnel in the measurement base.
6. Push the support rods (4x) on the top of the hood into the bracket. The hood is installed.

Large hood (1220x610 mm, 1220x305 mm and 915x915 mm, accessories)

Diagrams illustrate the setup:

1. Install the aluminium frame and stretch the fabric hood over the framework, so that the elastic band lies in the recess of the frame. Make sure that the elastic band fits correctly, especially at the corners.
2. Pull the lower end of the hood over the measurement base.
3. Attach the hood at two corners using the snap fasteners.
4. Tighten the closure.
5. Screw together a short and long section of the support rods (4x) at the silver ends.
6. Push the support rods (4x) through the hood, along the markings and into the funnel in the measurement base.
7. Push the support rods (4x) on the top of the hood into the bracket. The hood is installed.

Attaching the measuring instrument

Images show the instrument being attached:

1. Push the testo 420 completely into the instrument holder, pay attention to the catch on the right-hand and left-hand side in the bracket.

7.4. Measuring

7.4.1. Volume flow measurement

• ✔️ The volume flow hood is fitted.
• 1. Switch on the instrument.
• 2. In the instrument settings, set the application volume flow hood and also the required measurement program: Single measurement or Continuous measurement.
• 3. Press [Start/Stop] on the testo 420, or the trigger on the measurement base to hold or start and stop the measurement.
• 4. Press [Save] to save the measurement data. Unsaved measurement data is lost once you carry out the next measurement.
• The target folder and file name are displayed, confirm with [Confirm] to save the measurement data under this name and in the selected folder.

7.4.2. Pitot tube measurement

1. Remove the testo 420 from the measurement base.
2. Connect the hoses to the testo 420 and to the Pitot tube.
3. Press [Menu] -> Application -> Pitot tube and there set the duct geometry, the Pitot tube factor and the temperature, and choose between actual and standard.
4. Select the required measurement program.

ℹ️ With a timed/multi-point measurement program, the required number of measuring points can be recorded using [Start/Stop]. To end the measurement, press and hold down [Start/Stop] for at least 3 s. At least one measuring point must be recorded before the measurement can be terminated.

5. Carry out the measurement.
6. Press [Save] to save the measurement data. Unsaved measurement data is lost once you carry out the next measurement.
7. The target folder and file name are displayed, confirm with [Confirm] to save the measurement data under this name and in the selected folder.

Pitot tube factor details:

• Pitot tubes from Testo, Pitot tube factor: 1.00
• Straight Pitot tubes from Testo, Pitot tube factor: 0.67
• Air flow velocity matrix 0699.7077, Pitot tube factor: 0.82
• For Pitot tubes from other manufacturers, refer to the instruction manual for the Pitot tube factor or ask your supplier.

7.4.3. Differential pressure measurement

1. Remove the testo 420 from the measurement base.
2. Connect the hoses to the testo 420 at + and -.
3. Press [Menu] -> Application -> Pressure only.
4. Carry out the measurement.
5. Press [Save] to save the measurement data. Unsaved measurement data is lost once you carry out the next measurement.
6. The target folder and file name are displayed, confirm with [Confirm] to save the measurement data under this name and in the selected folder.

7.5. Saving

ℹ️ A maximum of 99 measurements can be saved in one folder.

• Press [Menu] -> Memory -> [Navigation]. The folder overview is shown on the display. Create a new folder via New Folder.
• A maximum 100 folders can be created.

Open folder

• Using the [Navigation] keys, navigate to the required folder and press [Confirm]. The selected folder is opened and the individual files are displayed.

Delete folder

1. Using the [Navigation] keys, navigate to the required folder and press [Confirm].
2. Select the menu item Delete Folder and confirm with [Confirm]. The folder that you want to delete is shown on the display.
3. Confirm once again with [Confirm] in order to delete the folder, or cancel by pressing [ESC].

Set as Logging Folder

This setting establishes which folder is to be specified as the standard storage location for saving the measurements.

ℹ️ The folder which is set as the standard storage location is marked in black.

1. Using the [Navigation] keys, navigate to the required folder and press [Confirm].
2. Select the menu item Set as Logging Folder and confirm with [Confirm].
3. The selected folder is set as the standard storage location.
4. The stored location can be changed during the saving process.

Total Volume Flow

ℹ️ If data from single measurements is saved within a folder, the total volume flow of all measurements can be displayed using this function.

1. Using the [Navigation] keys, navigate to the required folder and press [Confirm].
2. Select the menu item Total Volume Flow and confirm with [Confirm]. The single measurements and the total volume flow are displayed.
3. Press [Save]. The result of the total volume flow is saved.

7.6. Transferring measurement data to the PC

ℹ️ No Bluetooth connection is possible while there is a connection to the PC. The existing Bluetooth connection is aborted.

ℹ️ The PC identifies the testo 420 as a removable medium. In the event of any formatting, please make sure that the FAT format is always selected under the file system.

1. Connect the testo 420 to your PC using the USB cable.
2. The testo 420 switches on automatically, a window appears on the PC, select Open folder here. The folders and files saved on your testo 420 are displayed. The files are available in the file format *.txt.

8 Maintaining the product

8.1. Cleaning the instrument

Warning: Do not use any aggressive cleaning agents or solvents! Mild household cleaning agents or soap suds may be used.

If the housing of the instrument is dirty, clean it with a damp cloth.

9 Tips and assistance

9.1. Questions and answers

9.2. Accessories and spare parts

For a complete list of all accessories and spare parts, please refer to the product catalogues and brochures or visit our website www.testo.com

If you have any questions, please contact your dealer or Testo Customer Service. The contact details can be found on the back of this document or on the Internet at www.testo.com/service-contact.

10 Authorizations

Product: testo 420
Mat.-No.: 0560 0420
Date: 31.07.2023

The use of the wireless module is subject to the regulations and stipulations of the respective country of use, and the module may only be used in countries for which a country certification has been granted. The user and every owner has the obligation to adhere to these regulations and prerequisites for use, and acknowledges that the re-sale, export, import etc. in particular in countries without wireless permits, is his responsibility.

Bluetooth SIG List

IC Warnings

CAN ICES-003(B)/NMB-003(B): This Class B digital apparatus complies with Canadian ICES-003. Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.

RSS-Gen & RSS-247 statement: This device contains licence-exempt transmitter(s)/receiver(s) that comply with Innovation, Science and Economic Development Canada's licence-exempt RSS(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device. L'émetteur/récepteur exempt de licence contenu dans le présent appareil est conforme aux CNR d'Innovation, Sciences et Développement économique Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes: (1) L'appareil ne doit pas produire de brouillage (2) l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.

Caution: Radio Frequency Radiation Exposure This equipment complies with radio frequency exposure limits set forth by the Innovation, Science and Economic Development Canada for an uncontrolled environment. This equipment should be installed and operated with a minimum distance of 20 cm between the device and the user or bystanders.

Co-Location: This device must not be co-located or operated in conjunction with any other antenna or transmitter.

Attention : exposition au rayonnement de radiofréquences Cet équipement est conforme aux limites d'exposition aux radiofréquences définies par la Innovation, Sciences et Développement économique Canada pour un environnement non contrôlé. Cet équipement doit être installé et utilisé avec un minimum de 20 cm de distance entre le dispositif et l'utilisateur ou des tiers.

Co-location Ce dispositif ne doit pas être utilisé à proximité d'une autre antenne ou d'un autre émetteur.

This instrument complies with Part 15C of the FCC Rules and Industry Canada RSS-210 (revision 8). Commissioning is subject to the following two conditions: (1) This instrument must not cause any harmful interference and (2) this instrument must be able to cope with interference, even if this has undesirable effects on operation. Cet appareil satisfait à la partie 15C des directives FCC et au standard Industrie Canada RSS-210 (révision 8). Sa mise en service est soumise aux deux conditions suivantes : (1) cet appareil ne doit causer aucune interférence dangereuse et (2) cet appareil doit supporter toute interférence, y compris des interférences qui provoquerait des opérations indésirables.

FCC Warnings Information from the FCC (Federal Communications Commission)

For your own safety Shielded cables should be used for a composite interface. This is to ensure continued protection against radio frequency interference.

FCC warning statement This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.

Caution Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. Shielded interface cable must be used in order to comply with the emission limits.

Warning This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Caution: Radio Frequency Radiation Exposure This equipment complies with radio frequency exposure limits set forth by the FCC for an uncontrolled environment.. This equipment should be installed and operated with a minimum distance of 20 cm between the device and the user or bystanders.

Co-Location: This device must not be co-located or operated in conjunction with any other antenna or transmitter.

Brazil Information Este equipamento não tem direito à proteção contra interferência prejudicial e não pode causar interferência em sistemas devidamente autorizados. Este equipamento não é apropriado para uso em ambientes domésticos, pois poderá causar interferências eletromagnéticas que obrigam o usuário a tomar medidas necessárias para minimizar estas interferências. Para maiores informações, consulte o site da Anatel – https://www.gov.br/anatel/pt-br/

KCC Warning 해당 무선 설비는 운용 중 전파혼신 가능성이 있음

Japan Information 当該機器には電波法に基づく、技術基準適合証明等を受けた特定無線設備を装着している。

Testo SE & Co. KGaA Contact Information

Testo SE & Co. KGaA
Celsiusstraße 2
79822 Titisee-Neustadt
Germany
Telefon: +49 7653 681-0
E-Mail: info@testo.de
Internet: www.testo.com