# RH300-NIST Extech Thermometer New

**Features**

-   NIST Traceable
-   Simultaneous display of %RH, Temperature and Dew point or Wet Bulb or Probe Temperature
-   Wet bulb measurements without slinging
-   Calculates T1-T2 differential (Air Temperature-External Probe Temperature) using optional probe
-   Unique sensor cap design twists to closed position for protection during storage
-   Switchable °F/°C temperature units with 0.1° resolution

**Specifications**

-   Humidity: 10 to 90%RH
-   Temperature (internal): -4 to 122°F (-20 to 50°C)
-   Temperature (external): -4 to 158°F (-20 to 70°C)
-   Dew Point: -90.4 to 122°F (-68.0 to 49.9°C)
-   Wet Bulb: -6.9 to 122°F (-21.6 to 49.9°C)
-   Dimensions: 7 x 1.9 x 1" (178.5 x 48.4 x 24.7mm)
-   Weight: 3.3oz (95g)

The RH300 is a compact meter that is ideal for field applications. Simultaneously displays relative humidity (10% to 90% RH), air temperature and dew point or wet bulb. Calculates T1-T2 differential (air temperature minus external probe temperature) using optional probe (TP890), and T2 minus dew point. Built-in protective sensor cap. Other features include Data Hold, Auto Power Off, and MAX/MIN reading. Complete with 2 AAA batteries.

## Details

- **Price:** 211.5 USD
- **Vendor:** Extech
- **Type:** Therm Met
- **Tags:** Extech, Manufacturers, Meters & DAQ, product_manual_group_2, Product_new, Thermometer

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 211.50 USD | In stock |

## Images

- RH300-NIST Extech Thermometer New

---

> Source: [ValueTronics](https://valuetronics.com/products/rh300-nist-extech-thermometer-new)
> Updated: 2026-05-21