September 2008

Focus on calibration

Calibration is the setting or correcting of a measuring device or base level, usually by adjusting it to match or conform to a dependably known and unvarying measure. The purpose of calibration is to eliminate or reduce bias in the user's measurement system relative to the reference base. Calibrators vary in form and function depending on the instruments with which they are designed to work.

Precision infrared calibrator

The 4180 Series Precision Infrared Calibrators-4180 and 4181-utilize the same size targets used and recommended by thermometer manufacturers and special design technology that assists in productively performing high-quality infrared thermometer calibrations without requiring a background in physics. The 4180 calibrator has a temperature range of -15°C to 120°C, with radiometric (non-contact infrared) display accuracy as good as ± 0.40°C; and the 4181 calibrator measures from 35°C to 500°C, with radiometric display accuracy also as good as ±0.35°C.

The 4180 series calibrators have features that allow users to address quality issues commonly not covered by other calibrators in the same class, including emissivity and size of source effect. Additional features including target stability, target uniformity, six-inch target diameter, traceable radiometric calibration, and compensation for the emissivity settings of the radiation thermometer being tested overcome some of the other most common limitations. In addition, sample calibration procedures for Fluke thermometers are built into the instrument to get users up and running with a minimum of training.

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Hart Scientific, www.hartscientific.com

Test/calibration system

The Advanced Modular Calibration System is a hand-held test and calibration system that combines an advanced, multi-function calibrator with pressure measurement and generation capability. Its modular concept allows its discrete components to be used as stand-alone instruments.

The Advanced Modular Calibration System uses three basic components to perform duties formerly requiring a wide range of different instruments. At its core is its advanced, electrical, frequency and temperature calibrator. This compact and robust multi-function unit can measure and source mA, mV, V, Ohms, frequency, and a variety of RTDs and thermocouples. Pressure measurement is provided by interchangeable pressure modules that attach to the calibrator via a carrier. The calibrator and the pressure modules can also attach to a pressure generation station to form a fully integrated, high performance pressure calibrator. Three pressure stations are available, enabling the generation of pneumatic pressure from 95% vacuum to 20 bar or up to 100 bar while hydraulic pressure capability is 0 to 1,000 bar.

The system's rugged and weatherproof multi-function DPI 620 calibrator has been designed with performance, ease of use and versatility in mind. The calibrator can be simply expanded by the addition of further hardware and software modules, including an Intecal field calibration and documentation manager, a wireless module, and a 300 Vac measurement probe.

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GE Sensing & Inspection Technologies, www.ge.com/sensing

Precision laboratory calibrator

The Millennium Series 3001 Precision Laboratory Calibrator combines the power and features of the M2001 (voltage, current, thermocouple, RTD, and pressure) with a second completely isolated measurement channel for a single laboratory calibration instrument unmatched in versatility, performance, and value. The 3001's feature set is accessed through a simple-to-use and intuitive user interface with pushbutton selection of functions and two clear brightly backlit displays.

The most important feature of the 3001 is the accuracy. DC accuracy is rated at ±0.0025% of reading. This DC accuracy specification translates into similar performance for measuring and simulating temperature with thermocouples and RTDs.

The 3001 includes a second isolated measurement channel to provide the complete loop for process instrument and transmitter calibration. The isolated measurement channel has two voltage ranges (10 VDC and 100 VDC); milliAmp measurement to 52 mADC; available 24 VDC loop power; a user switched 250 Ohm in loop HART resistor; and an accuracy of ±0.005% of reading on voltage ranges. In voltage mode, the 3001 offers four (4) output ranges of 100 mV, 1 V, 10 V and 100 V DC.

Martel Electronics Corporation, www.martelcorp.com