Surface Dial Thermometer. Surface Dial Thermometers are designed for quick and accurate temperature measurement of various surfaces. They use a bimetal sensing element to provide reliable readings and are ideal for industrial, laboratory, and HVAC applications. Specifications Temperature Range: Available in multiple ranges, including 0°–250°F (-15°–120°C) and 0°–500°F (-20°–260°C) Dial Size: 2-inch (50.88mm) diameter Accuracy: ±2% of full scale Mounting: Two integral magnets for placement on ferrous surfaces Response Time: Approximately 1 minute Material: Aluminum case with optically clear crystal Uses HVAC system monitoring Industrial equipment temperature tracking Laboratory research and testing Automotive and aerospace applications Product Details Brand: Omega™, Gilson™, Fisherbrand™ Models: SUR-15, SUR-25, SUR-50, SUR-75 Features: Dual Fahrenheit & Celsius dials, durable construction Price Range: $44.00 - $116.63