Introduction

Duratemp Thermometers

® thermometer offersthe same outstanding quality and craftsmanship which has character- ized all Ashcroft products since the introduction of the Bourdon tube to American industry in 1852.Uncompromising standards havebeen established for materials and workmanship. The finished product assures the user of superior durabil-ity and dependability.All Duratemp thermometers useand actuation concept unique to the field of temperature measurement, called a “molecular sieve.” This design represents a technical advancement over conventional gas and mercury thermometers.Research and development of amolecular sieve thermometer began in 1964 when the US Navy asked thermometer manufacturers to develop a remote thermometer that was both linear and mercury free. In 1970 Dresser received Navy approval on the molecular sieve thermometer and for over a decade was the only manufacturer to com- ply with the Navy’s rugged require- ments. Today’s Duratemp is a direct offshoot of the Navy thermometer, and incorporates in its design all the features found in the original Navy design.The superiority of a Duratemp ther-mometer is revealed by comparison to conventional thermometry. Conventional gas thermometers operate on the principle that the absolute pressure is proportional to theabsolute temperature. To obtain a usable temperature span, elevated working pressures must be used which frequently produce high stresses in the Bourdon tube. These high stresses reduce instru- ment life and may be hazardous.The Duratemp thermometer on theother hand utilizes a combination of inert gas and activated carbon called a molecular sieve. This com- bination produces much lower inter- nal pressures than conventional thermometers for the same temper- ature span. These lower pressures are transmitted to a compact helical Bourdon tube. The Bourdon tube connects directly to the pointer shaft thus eliminating the traditional movement assembly. With this advantage the Duratempthermometer is able to provide long life and sustained accuracy under the most adverse shock and vibra- tion conditions.The molecular sieve concept, uti-lized by Dresser in its Duratemp thermometer, offers a host of fea- tures, functions and benefits that make it superior to any conventional mechanical thermometer on the market today.Duratemp thermometers are avail-able through our extensive distribu- tor network and our manufacturing plant in Stratford, CT.

Mercury Free

Gas Filled

• NIOSH and OSHA compliance for mercury contaminationhazards. Protects personnel and processes from accidental contamination.

No Head or Elevation Error

• Accurate readings are ensured even if the industrial bulb is mounted above or below the case.

Shock and Vibration Resistance

Unique Direct Drive Bourdon Tube

• Gear and pinion movements are eliminated, result-ing in increased instrument life and reducedreplacement costs.• Silicone damped Bourdon tube eliminatesdamage from shock and vibration. The Duratemp