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IR Ratio Pyrometer suits high-temperature applications.

Press Release Summary:

IR Ratio Pyrometer suits high-temperature applications.

Nov 30, 2009 - Non-contact thermal sensor thermoMETER CT is suited for measuring temperature of metals, metal oxides, ceramic, and semiconductor materials from 700 to 1,800°C. Fiber optic pyrometer, insensitive to contaminants, provides faultless measurements and operates on 2-channel principle. Response times of 5 ms can be realized, and 25 mm dia x 70 mm long sensor head enables mounting in space-restricted areas. Additionally, sensor offers optical resolution of 80:1 with selectable focus.

Micro-Epsilon UK Ltd - Cheshire, GBR

Original Press Release

Ratio Pyrometer Sets New Benchmark in Low Cost Measurement of Difficult High Temperature Applications

Press release date: Nov 23, 2009

Micro-Epsilon has expanded its range of non-contact infrared temperature sensors to include a new compact infrared ratio temperature sensor (ratio pyrometer).

The new thermoMETER CT ratio pyrometer is ideal for OEMs that need to measure the temperature of metals, metal oxides, ceramic or semiconductor materials in harsh, high temperature environments, including metal casting, welding, forming and sintering.

The thermoMETER CT ratio is a fibre optics ratio pyrometer that measures temperatures from 700°C up to 1,800°C. The sensor functions according to the ratio principle and is therefore insensitive to contaminants such as dust, smoke or steam that may partially obstruct the target. Even in cases where the infrared radiation beam is weakened to 95 per cent of its original intensity due to smoke or steam, the ratio pyrometer still provides faultless measurements.

The compactness and attractive price-performance ratio of the pyrometer set new standards for use in OEM applications and where application flexibility is required. Chris Jones, Managing Director at Micro-Epsilon (UK) Ltd comments: "The CT ratio is another market leading product from Micro-Epsilon. Technically, the product meets and exceeds the performance of all ratio pyrometers in the marketplace today, with the flexibility of multiple output options and output signal flexibility, from simple analogue to digital and fieldbus interfaces. The low price level of just £1,950 for the system is significantly below the price level of other ratio pyrometers and enables users to solve applications with this technology that previously were cost-prohibitive."

The fibre optics ratio pyrometer operates on the two-channel measurement principle. Two integrated infrared detection channels with relatively close spacing, but with mutually different measuring wavelengths, produce two independent electrical signals. These signals depend on the infrared radiation emitted from the target and signal components, which are influenced by the optical transmission path between the object and the pyrometer, or from changes of the object if for example, it is moving or changes its size.

By taking the ratio of the two signals, the ratio pyrometer principle eliminates (or averages out) any signal parts that are similar in both channels. The measured temperature of the object therefore only depends on the signal ratio and the emissivity ratio, or 'slope value'.

When it comes to measuring the temperature of objects with unknown or changing emissivity, the ratio thermometer principle provides extremely accurate results, assuming that the emissivity ratio is not changing over time or temperature.

The compact sensor head of the ratio pyrometer has a diameter of just 25mm and a length of 70mm, enabling it to be mounted into tight, restricted spaces in production lines and machines. A fibre optic cable connects the optical sensor head to the electronics. The optics and the cable can be used in ambient temperatures of up to 250°C without the need for additional cooling. By using a fibre optic cable, the device is insensitive to electromagnetic interference (EMI) normally found in induction-based heat treatment processes.

Rapid temperature measurements with response times of 5ms can be achieved. An optical resolution of 80:1 with a selectable focus, in combination with built-in laser aiming, enables accurate measurements from a spot size of 1.3mm.

In order to adapt the sensor to different measurement tasks, the pyrometer offers a choice of a one- or two-channel (ratio pyrometer mode) device, which enables the user to select the most appropriate one without having to purchase additional infrared sensors.

Typical applications for the ratio pyrometer include the temperature control of inductive heating coils, temperature measurement of the pouring stream on casting machines; during the reheating of steel ingots and steel billets in forging processes; in general soldering and welding processes; and in process steps in semiconductor production and in photovoltaics.

The electronics enable the programming of the sensor, display of temperature measurements and easy wiring of the analogue outputs 0/4-20mA and 0-5/10V for the transmission of signals into industrial control cabinets. To facilitate network integration, Micro-Epsilon offers an optional integrated Profibus DP interface or other plug-in digital interfaces including USB, RS232, RS485 or Ethernet. Programmable signal processing ensures complete flexibility for different production processes.

Micro-Epsilon also offers its user-friendly software that provides graphical interface and display, the logging of temperature readings of all output channels and signal characteristics over time. The user can also configure parameters and set up alarms such as 'dirty lens' alarms.

The standard focus of the lens is 60mm. However, an additional, variable focus lens can be provided, which enables the user to set the focal point of the lens between 65mm and 300mm.

For more information on the thermoMETER CT ratio, please call the Micro-Epsilon sales department on 0151 355 6070 or email:

Micro-Epsilon ( is a major global manufacturer of sensors, headquartered in Germany. The company's range of displacement sensors measure everything from to distance, position, vibration, dimensions and thickness, using both contact and non-contact measurement techniques. These techniques include 1D, 2D and even 3D laser-optical sensors and systems, eddy-current, capacitive, LVDT & inductive, potentiometric and draw-wire principles. Additionally Micro Epsilon has developed its own range of non-contact infrared temperature sensors that can measure virtually any target temperature from -40 to +3,300°C.

With more than 30 years' experience in the industry, Micro-Epsilon isn't just a sensor manufacturer. The company is highly innovative and understands the importance of providing complete solutions and support services for its customers. The firm is renowned for its expertise in consulting, development and application of industrial sensors to complex, customer-specific solutions for measurement, inspection and automation. The focus is on selling technical advantage to its customers.