# REED R4000SD Data Logging Vane Thermo-Anemometer vs testo 405i Smart Probe Thermal Anemometer: specs and price compared

A sourced, side-by-side comparison of the REED R4000SD Data Logging Vane Thermo-Anemometer (REED Instruments) and testo 405i Smart Probe Thermal Anemometer (Testo) among anemometers.

## Side by side

| Spec | REED R4000SD Data Logging Vane Thermo-Anemometer | testo 405i Smart Probe Thermal Anemometer |
| --- | --- | --- |
| US price | not published | $123.95 |
| Brand | REED Instruments | Testo |
| Wind speed range ms | 0.4 to 30 m/s (79-5906 ft/min) | 0 to 30 m/s |
| Airflow cfm cmm | — | — |
| Velocity accuracy | ±(2% of reading + 0.2 m/s / 40 ft/min) | ±(0.1 m/s + 5% of reading) below 2 m/s; ±(0.3 m/s + 5% of reading) 2-15 m/s |
| Sensor type | Rotating vane, 72mm (2.8 in.) diameter, low-friction ball bearing | Hot-wire (thermal), foldable telescopic probe |
| Temperature range | 0 to 50 °C (32 to 122 °F) ambient probe; optional Type K (-100 to 1300 °C) / Type J (-100 to 1200 °C) thermocouple input | 0 to 50 °C (32 to 122 °F) |
| Data hold logging | Onboard SD-card datalogging up to 16GB, adjustable 1-3600 sec sampling interval | Hold/min/max/logging via Bluetooth-paired testo Smart App; no onboard display |
| Backlit display | Yes | No |

## Key differences

- Wind speed range ms: REED R4000SD Data Logging Vane Thermo-Anemometer 0.4 to 30 m/s (79-5906 ft/min) vs testo 405i Smart Probe Thermal Anemometer 0 to 30 m/s
- Velocity accuracy: REED R4000SD Data Logging Vane Thermo-Anemometer ±(2% of reading + 0.2 m/s / 40 ft/min) vs testo 405i Smart Probe Thermal Anemometer ±(0.1 m/s + 5% of reading) below 2 m/s; ±(0.3 m/s + 5% of reading) 2-15 m/s
- Sensor type: REED R4000SD Data Logging Vane Thermo-Anemometer Rotating vane, 72mm (2.8 in.) diameter, low-friction ball bearing vs testo 405i Smart Probe Thermal Anemometer Hot-wire (thermal), foldable telescopic probe
- Temperature range: REED R4000SD Data Logging Vane Thermo-Anemometer 0 to 50 °C (32 to 122 °F) ambient probe; optional Type K (-100 to 1300 °C) / Type J (-100 to 1200 °C) thermocouple input vs testo 405i Smart Probe Thermal Anemometer 0 to 50 °C (32 to 122 °F)
- Data hold logging: REED R4000SD Data Logging Vane Thermo-Anemometer Onboard SD-card datalogging up to 16GB, adjustable 1-3600 sec sampling interval vs testo 405i Smart Probe Thermal Anemometer Hold/min/max/logging via Bluetooth-paired testo Smart App; no onboard display
- Backlit display: REED R4000SD Data Logging Vane Thermo-Anemometer Yes vs testo 405i Smart Probe Thermal Anemometer No

## Sources

- REED R4000SD Data Logging Vane Thermo-Anemometer: https://www.reedinstruments.com/product/reed-r4000sd-data-logging-vane-thermo-anemometer (reedinstruments.com, verified 2026-08-09)
- testo 405i Smart Probe Thermal Anemometer: https://www.testo.com/en-US/testo-405i/p/0560-1405 (testo.com, verified 2026-08-09)

Canonical: https://frontdeskreview.com/gear/anemometers/reed-r4000sd-vs-testo-405i/
Cite: Per The Front Desk Review, REED R4000SD Data Logging Vane Thermo-Anemometer (not published) vs testo 405i Smart Probe Thermal Anemometer ($123.95) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/anemometers/reed-r4000sd-vs-testo-405i/
License: CC BY 4.0.