# Extech 45158 Mini Thermo-Anemometer with Humidity vs REED R4000SD Data Logging Vane Thermo-Anemometer: specs and price compared

A sourced, side-by-side comparison of the Extech 45158 Mini Thermo-Anemometer with Humidity (Extech Instruments) and REED R4000SD Data Logging Vane Thermo-Anemometer (REED Instruments) among anemometers.

## Side by side

| Spec | Extech 45158 Mini Thermo-Anemometer with Humidity | REED R4000SD Data Logging Vane Thermo-Anemometer |
| --- | --- | --- |
| US price | not published | not published |
| Brand | Extech Instruments | REED Instruments |
| Wind speed range ms | 1.1 to 20 m/s (2.5-44.7 mph) | 0.4 to 30 m/s (79-5906 ft/min) |
| Airflow cfm cmm | — | — |
| Velocity accuracy | ±(3% of reading + 0.4 mph) | ±(2% of reading + 0.2 m/s / 40 ft/min) |
| Sensor type | Vane, 1 in. (24mm) diameter | Rotating vane, 72mm (2.8 in.) diameter, low-friction ball bearing |
| Temperature range | -18 to 50 °C (0 to 122 °F), ±1 °C accuracy | 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 |
| Data hold logging | Data hold; selectable 5/10/13-second averaging (no onboard SD/USB logging) | Onboard SD-card datalogging up to 16GB, adjustable 1-3600 sec sampling interval |
| Backlit display | Yes | Yes |

## Key differences

- Wind speed range ms: Extech 45158 Mini Thermo-Anemometer with Humidity 1.1 to 20 m/s (2.5-44.7 mph) vs REED R4000SD Data Logging Vane Thermo-Anemometer 0.4 to 30 m/s (79-5906 ft/min)
- Velocity accuracy: Extech 45158 Mini Thermo-Anemometer with Humidity ±(3% of reading + 0.4 mph) vs REED R4000SD Data Logging Vane Thermo-Anemometer ±(2% of reading + 0.2 m/s / 40 ft/min)
- Sensor type: Extech 45158 Mini Thermo-Anemometer with Humidity Vane, 1 in. (24mm) diameter vs REED R4000SD Data Logging Vane Thermo-Anemometer Rotating vane, 72mm (2.8 in.) diameter, low-friction ball bearing
- Temperature range: Extech 45158 Mini Thermo-Anemometer with Humidity -18 to 50 °C (0 to 122 °F), ±1 °C accuracy vs 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
- Data hold logging: Extech 45158 Mini Thermo-Anemometer with Humidity Data hold; selectable 5/10/13-second averaging (no onboard SD/USB logging) vs REED R4000SD Data Logging Vane Thermo-Anemometer Onboard SD-card datalogging up to 16GB, adjustable 1-3600 sec sampling interval

## Sources

- Extech 45158 Mini Thermo-Anemometer with Humidity: https://www.extech.com/products/45158 (extech.com, verified 2026-08-09)
- 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)

Canonical: https://frontdeskreview.com/gear/anemometers/extech-45158-vs-reed-r4000sd/
Cite: Per The Front Desk Review, Extech 45158 Mini Thermo-Anemometer with Humidity (not published) vs REED R4000SD Data Logging Vane Thermo-Anemometer (not published) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/anemometers/extech-45158-vs-reed-r4000sd/
License: CC BY 4.0.