Testo 425 Compact Thermal Anemometer
£408.00 / £489.60 incl VAT
⚡ Measure air flow velocity and air temperature
⚡ Calculate volume flow by entering duct channel area
⚡ Extendable telescopic probe with 820mm maximum extension
Only 1 left in stock (can be backordered)
Description
Testo 425 Compact Thermal Anemometer
Product Descriptions:
The Testo 425 Compact Thermal Anemometer is an extremely useful instrument for use in the HVAC sector, particularly ascertaining air flow and temperature readings in ventilation ducts. This is because of the compact ø7.5mm diameter sensor that sits on top of a telescopic probe with a maximum length of 820mm. The use of a hot-wire probe rather than a vane also means that it is easier to position the meter at an appropriate angle. The anemometer had an air flow velocity range of 0 to 30m/s and a temperature range of -20˚C to 70˚C whilst volume flow can also be calculated if the user enters the cross-sectional area of the duct.
The large, backlit, digital screen on the Testo 425 shows results for air flow, volume flow and temperature in m/s, m3/h and ˚C. It is capable of showing two readings simultaneously and also offers min/max values alongside data hold. Further measurement options include point and timed mean value calculation. The anemometer has a 35-hour battery life and is also provided with batteries and a calibration protocol certificate. The Testo 425 has a robust and durable design, with a protection class rating of IP40 for the instrument and IP20 for the probe.
Key Features:
- Air flow velocity range: 0 to 30m/s
- Air flow velocity accuracy: ±(0.03 m/s + 4% of m.v.) (0 to 20 m/s) ±(0.5 m/s + 5% of m.v.) (20.01 to 30 m/s)
- Air flow velocity resolution: 0.01m/s
- Temperature range: -20˚C to 70˚C
- Temperature accuracy: ±0.5˚C
- Temperature resolution: 0.1˚C
- Volume flow calculation
- 820mm telescopic probe
- Point and timed mean values
Testo Smart App
The Testo Smart App supports the user being able to configure the measuring instrument. Users are able to view graphical measure value curve. Using a smart device with the downloaded app, users are able to turn their smart device into a second screen.
The Testo Smart App allows for operation, measurement and documentation of all compatible Bluetooth enabled Testo measuring instruments. With its intuitive measurement menus, quick configuration, the Testo Smart App is simple to use and allows for uncomplicated documentation to be completed. Measurements can be found quickly and easily with data shown in graphical and tabular curve display.
The App allows for data to be stored alongside customer information. Reports can be easily generated, including photos as PDF/CSV files and emailed directly from the smart device to colleagues or customers.
Data can be transferred to a PC using Testo’s PC software DataControl. The App benefits from continuous updates and extensions.
Testo part number:0563 0425
What’s In The Box?
- Testo 425
- Fixed telescope (max 820mm)
- 3 X AA batteries
- Transport bag
- Calibration protocol
| Temperature – NTC | |
|---|---|
| Measuring Range | -20 to +70 °C |
| Accuracy | ±0.5 °C |
| Resolution | 0.1 °C |
| Velocity – Thermal Anemometer | |
| Measuring Range | 0.01 to 30 m/s |
| Accuracy | ±(0.03 m/s + 4.0 % of mv) (0.01 to +20 m/s), ±(0.5 m/s + 5.0 % of mv) (20.01 to +30 m/s) |
| Resolution | 0.01 m/s |
| General Technical Data | |
| Weight | 268 g |
| Dimensions | 135 x 60 x 28 mm |
| Operating Temperature | -20 to +50 °C, Probe: -20 to +70 °C |
| Product-/Housing Material | ABS + PC / TPE |
| Diameter Probe Shaft | 7.5 mm |
| Cable Length | 1.5 m |
| Protection Class | IP40, IP20 |
| Length Probe | 180 mm |
| Battery Type | 3x AA |
| Battery Life | 35 h |
| Storage Temperature | -20 to +50 °C |
- Testo 425
- Fixed telescope (max 820mm)
- 3 X AA batteries
- Transport bag
- Calibration protocol
🚚 Testersmans Shipping Policy
Free Mainland GB Delivery Over £150
We offer free delivery on most mainland Great Britain orders over £150 (ex VAT).
This applies across England, Wales, and most of Scotland, excluding certain remote or offshore postcodes.
If your order total falls just short of £150, or you’re a returning customer, feel free to contact us — we may be able to offer a discount code or delivery workaround.
📞 01945 738112 | ✉️ sales@testermans.co.uk
📦 UK Delivery Options
We work with both Royal Mail and DHL to offer reliable and flexible delivery across the UK:
- Royal Mail – Best suited for lighter parcels and for customers in remote regions, including the Highlands, Islands, and Northern Ireland.
- DHL – Ideal for most mainland UK orders, providing fast, tracked delivery and excellent reliability for time-sensitive shipments.
Our checkout system automatically displays the available delivery services for your postcode and order weight, ensuring you always see the most suitable options.
Note: Heavy, bulky, or freight-only orders will be charged separately.
Our website is designed for quick, transactional purchases rather than bulk or palletised orders.
Please contact us in advance for a tailored freight quotation if your order falls into this category.
⏱ Dispatch & Delivery Timing
We aim to dispatch all in-stock orders promptly, but delivery depends on both when you order and which service you select.
- UK orders: placed by 2:00 PM Monday–Friday are usually dispatched the same day.
- International orders: placed by 2:00 PM Monday–Thursday are usually dispatched the same day.
Orders placed after these times are processed the next working day. This means delivery may occur the following day or later, depending on the courier and service selected.
Once dispatched, your chosen delivery service determines how quickly your parcel arrives:
- Standard services We use Royal Mail Tracked 24 or DHL Parcel as our ‘Standard’ services. They are not guaranteed to arrive next working day.
- Premium services (e.g. Royal Mail Special Delivery or DHL by Noon) offer guaranteed delivery windows.
If your order is time-sensitive, we strongly recommend choosing a guaranteed service or contacting us before ordering to confirm availability.
Please note: For logistical reasons, we may occasionally adjust the delivery method selected at checkout. For example, smaller items may be better suited to letterbox-friendly packaging or may be at greater risk of delay or loss via certain services. We actively monitor courier and postal service disruptions—including strikes and delays—and may modify shipping arrangements to help ensure timely and secure delivery.
📅 Busy Periods & Delays
We always aim to dispatch promptly, but delivery times may be affected by:
- Seasonal demand (e.g. Christmas, bank holidays, or industry shutdowns)
- Courier network delays outside our control
- Supplier lead times or calibration requirements for certain equipment
If your delivery is time-critical, please contact us before ordering so we can confirm stock and courier availability.
🌍 International Shipping
We ship worldwide using UPS Express Saver® and other trusted global courier partners. All international shipments are tracked and generally dispatched Monday to Thursday to ensure smooth customs clearance and transit.
Estimated delivery times:
- Europe: 1–2 working days
- North America: 2–3 working days
- Asia-Pacific & Rest of World: 3–5 working days
Delivery times vary depending on location, customs clearance, and local courier performance.
💰 Taxes, Customs & Import Duties
International customers are responsible for any applicable taxes, customs charges, or import duties.
These are not included in our product or shipping prices.
Your courier will typically provide a secure payment link for any import charges once your parcel reaches customs.
If import fees are refused and the parcel is returned, we will issue a refund minus all incurred shipping and return costs.
📍 Using Your Own Courier
If you would prefer to arrange collection via your own courier (UK or international), please contact us before placing your order to coordinate collection from our Wisbech warehouse.
📝 Important Notes
- Please ensure your delivery address and contact number are correct at checkout.
- Undelivered parcels may be returned to us after a short holding period.
- Redelivery or return fees may apply, even if your order originally qualified for free delivery.
- By placing an order, you confirm your understanding and acceptance of this policy.
Additional information
| Weight | 268 g |
|---|