• Case: sturdy, corrosion resistant series 304 stainless steel case and bezel
• Crystal: optically clear, strong glass, gasketed to maintain weather-tight integrity is standard
• Stem: 304 series stainless steel, welded at tip and case connector to prevent leakage, 1/4" (6.35 mm) diameter is standard
• Hermetic seal: hermetically sealed per ASME B40.3 external reset: slotted-hex adjustment head offers screwdriver or wrench use to field calibrate the thermometer
• Bi-metal element: an extremely responsive temperature sensing helix which has been carefully sized and tested, heat treated and aged to relieve inherent stresses and insure continued accuracy
• Dampening: bi-metal helix is coated with a viscous silicone to minimize pointer oscillation and to improve temperature transmission

Model 31

Accuracy: guaranteed to be accurate to within 1% of full scale (Grade A per ASME B40.3) (The American Society of Mechanical Engineers issued a new standard for Bi-Metal Thermometers in 1990 referred to as ASME B40.3.)

• Immersion: for accurate temperature readings, immerse stem a minimum of 2" (50 mm) in agitated liquids or 4" (100 mm) in moving air or gas
• Over range: temporary over or under range of 50% of scale up to 260°C or 500°F will not affect the instrument accuracy