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Advantages of AC resistance thermometry bridges

Advantages of AC resistance thermometry bridges
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Advantages of AC resistance thermometry bridges - 1

Calibration technology thermometry bridges

Advantages of AC resistance thermometry bridges - 2

Resistance thermometry bridges By using internal or external standard resistors (model CER6000), resistance thermometry bridges measure resistance ratios with high accuracy, which are indicative of the temperature, among other things. Due to their high accuracy, these instruments are not only used in the field of temperature measurement, but also in electrical laboratories. ASL equipment is used for research, primary and secondary calibration verification, process monitoring, sterilisation and validation work by some of the world’s most demanding end users in the Aerospace, Pharmaceutical,...

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Advantages of AC resistance thermometry bridges - 3

Precision thermometer AC resistance thermometry bridge Primary-standard resistance thermometry bridge Accuracy: 0.1 … 1.25 mK depending on resistance ratio Sensor type: SPRT, PRT or fixed resistor Sensor type: SPRT, PRT or fixed resistor Special feature: Integrated data logger (optional) Up to 64 channels Special feature: Expendable to up to 60 channels (optional) Internal resistors 25, 100 Ω AC technology Special feature: Expendable to up to 60 channels (optional) 4 selectable standby currents possible (optional) AC technology CTR6000 DC resistance thermometry bridge Measuring range: -200...

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Advantages of AC resistance thermometry bridges - 4

Heart of the AC bridge concept The ratio transformer The ratio transformer is sometimes referred to as an IVD, an Inductive Voltage Divider. As suggested by its name the “simple” task of the ratio transformer is to divide the voltage across the resistance thermometer RT and a reference resistor RS, which carry a common current, and therefore measure the ratio VT / VS, which is the same as the ratio RT / RS. bridge is a super accurate voltage divider Direct Current (DC) A traditional method for measuring resistance accurately in this way is the Wheatstone bridge, this is made of two...

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Advantages of AC resistance thermometry bridges - 5

Alternating Current (AC) A simplified diagram of an AC bridge is shown below, the voltage across the standard RS is measured by the fixed primary winding (P) of the ratio transformer. The secondary winding (S), or the variable, can be adjusted so the voltage division is equal to that of RT to RS. The secondary winding (S) is far from a simple secondary and can be shown to take the form of cascaded “decades”, which can be considered similar in principle to that of the decade resistor box. In effect, one tapping of the “unity ratio” decade has ten tappings which represent “0.1” ratio each. So...

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Advantages of AC resistance thermometry bridges - 6

High accuracy Accuracy is inherent in the design of ASL bridges, ASL use AC measurement techniques in its bridges because the AC ratio technique is the best ratio standard able to provide higher precision. Long-term stability The Ratio transformer (Inductive Voltage Divider) does not drift with time and has proven to have long term stability providing consistent measurement results. Elimination of DC circuit drifts By using AC the amplifier drifts associated with DC instruments are not a problem, therefore providing good stability and fast measurements. Low temperature coefficient The ratio...

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Advantages of AC resistance thermometry bridges - 7

Our temperature measuring bridges are mainly used to measure and calibrate temperature sensors. Our products make your measurements and calibrations very easy. This is ensured through intuitive operation and very precise measurement technology. Automotive industry Calibration of high-precision automotive sensors and transmitters. Heating, ventilation, air-conditioning Accurate measurements for applications such as air-conditioning, water heating and cooling systems. Manufacturing of temperature sensors Measurement of process-critical parameters during manufacture. Pharmaceutical industry...

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Advantages of AC resistance thermometry bridges - 8

High Precision Standard Platinum Resistance Thermometer (SPRT) Standard reference resistor Long-term stability: 2 ppm per year (HS version 0.5 ppm per year) Special feature: Low temperature coefficient Rugged stainless steel construction Special feature: Free cable ends, DIN or SMART connector Highest precision for each requirement In addition to the umbrella brand WIKA, you will also find the brand ASL for the measurement parameter temperature. With these established brands within the calibration market we deliver the ideal solution for each measurement task. The products of ASL can be...

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