Miniature Uncooled and Unchopped Fiber Optic Infrared Thermometer for Application to Cutting Tool Temperature Measurement

Abstract

A new infrared thermometer, sensitive to wavelengths between 3 μm and 3.5 μm, has been developed. It is based on an Indium Arsenide Antimony (InAsSb) photodiode, a transimpedance amplifier, and a sapphire fiber optic cable. The thermometer used an uncooled photodiode sensor and received infrared radiation that did not undergo any form of optical chopping, thereby, minimizing the physical size of the device and affording its attachment to a milling machine tool holder. The thermometer is intended for applications requiring that the electronics are located remotely from high-temperature conditions incurred during machining but also affording the potential for use in other harsh conditions. Other example applications include: processes involving chemical reactions and abrasion or fluids that would otherwise present problems for invasive contact sensors to achieve reliable and accurate measurements. The prototype thermometer was capable of measuring temperatures between 200 °C and 1000 °C with sapphire fiber optic cable coupling to high temperature conditions. Future versions of the device will afford temperature measurements on a milling machine cutting tool and could substitute for the standard method of embedding thermocouple wires into the cutting tool inserts. Similarly, other objects within harsh conditions could be measured using these techniques and accelerate developments of the thermometer to suit particular applications.

A Comparative Review of Thermocouple and Infrared Radiation Temperature Measurement Methods during the Machining of Metals

“…The temperature monitoring techniques found in the literature fall into two main categories: contact (or conductive) and non-conduct (or radiative) techniques, as summarised in Figure 2 [31,53]. Detailed summaries of background theory of these methods and their uncertainties were provided by Childs [51] and Nicholas and White [54], with Heeley et al [55] providing an uncertainty analysis for their custom fibre-optic infrared thermometer.…”

High Spatial Resolution Optical Fiber Two Color Pyrometer With Fast Response

“…6, taking a distance between the fiber end and the target surface of 25 µm. Table 1 demonstrates the widespread use of large core fiber diameters in pyrometry applications to enhance the light gathering [10], [16], [19]. Some proposals also include optical lenses placed at the fiber end to help the probe to improve the light gathering and focusing capabilities [20].…”

Thermometry in Laser Micro/Nanofabrication

“…In some special cases, an optical fiber is used to remotely transfer the infrared radiation single from the optical system to a detector, to avoid the detector from working at the harsh working environment (Heeley et al 2018).…”