Reotemp Gas Actuated Thermometer From Reotemp Instruments Gas Actuated Bourdon Tube Drive Accuracy: ± 1% of full scale. Calibration to NIST traceable standards. Dial Sizes: 4-1/2" & 6". Dials are white with black markings. Ranges: -320 to 1200°F or °F/°C Case Materials: Stainless steel, Phenolic, or Aluminum. Case Styles: Panel Mount (remote), Surface Mount (remote, or Direct (stem) Mount. Windows: Glass is standard. Shatterproof glass and acrylic are optional. Pointer: Slotted adjustable type to permit zero-set adjustments. Bulbs: 316 Stainless Steel, 3/8" diameter x 3" active length. Other diameters and lengths are available. Actuation: Nitrogen thru stainless steel bourdon tube.