Mass Calibration Laboratories & Our Calibration System
Calibration & Traceability Philosophy
Troemner is the world's largest independent mass calibration company. Our philosophy is to provide the highest level of calibration quality by pursuing every measurement detail in order to achieve the most accurate and repeatable calibrations in the industry. We produce a precise measurement starting with a stable and tightly controlled environment, followed by using the finest equipment available, with highly trained personnel executing proven procedures. Our goal is to provide our customers with the lowest measurement uncertainties achievable.
World Class Calibration Facilities
The backbone of our calibration capabilities is the design, construction, and operation of our physical facilities. Troemner's Mass Calibration Laboratories were constructed to meet the strict environmental guidelines listed in NIST/NVLAP Handbook 150-2.
In order to maintain the strictly controlled environment, the Mass Calibration Laboratories were designed and constructed as a building within a building. With Troemner's corporate headquarters, three Echelon I Laboratories and one Echelon II Laboratory sit upon separate 30" foundations that are isolated from the rest of the building with layers of sand and concrete to eliminate vibration. The walls are 12" thick and provide a temperature and vapor barrier to the outside. The climate in each of the Mass Calibration Laboratories is strictly monitored and controlled with each laboratory having its own HVAC system. Temperature in the laboratory is measured to 0.05°C and maintained at 21.5 ± 1°C with no more than a 0.5°C change per hour. Humidity is measured to ± 2% and maintained within 40-50%, with no more than a 5% change per hour. Barometric pressure is measured to 0.01 mm Hg. Although the temperature and humidity are tightly measured and controlled, the deign of the air handling system allows for minimal air velocity so air currents are kept to a minimum.
Cutting Edge Equipment
All mass comparators used in Troemner's Mass Calibration Laboratories are state-of-the-art with the highest precision possible. Troemner can measure as precisely as 0.0001 mg. Each comparator rests on a marble table to reduce the effects from vibration and has its own temperature probe mounted within the weighing chamber to measure the temperature at the time of calibration. The comparators are interfaced to a host computer outside the laboratory for processing calibration data. Troemner's custom software programs ensure the accuracy of the data collection and calculation process. Troemner's metrologists and calibrators are equipped with mass standards directly traceable to NIST (National Institute of Standards and Technology) and NPL (National Physical Laboratory).
Troemner's precision weights are sampled regularly throughout the manufacturing process to determine the magnetic properties of the material. Stainless steel is tested for magnetic permeability and for magnetic susceptibility. Once Troemner's two-piece weights are machined and polished, they are checked using a Gaussmeter prior to the calibration. Troemner's stainless steel one-piece weights are all individually tested for magnetic susceptibility using a state-of-the-art susceptometer. Troemner's susceptometer procedure is based on Dr. Richard Davis' paper, "Determining the Magnetic Properties of 1 kg Mass Standards". Working in collaboration with Dr. Davis and Dr. Nava-Martinez (CENAM), Troemner metrologist, Joe Moran, has completed an inter-laboratory comparison with several internationally recognized metrology organizations to determine the effectiveness of the susceptometer which is summarized in the technical paper, "Intercomparison Between CENAM, BIPM, and Troemner to Determine the Volume Magnetic Susceptibility of a 100 g Weight".
Troemner's traceability to nationally recognized standards is guaranteed. Direct traceability to NIST and NPL is achieved and maintained through the use of several standards that are not only returned to NIST and NPL on a regular schedule, but also are intercompared in our laboratories to monitor their stability.