Glass bulbs for Xenon or halogen lamps require a very reproducible control of the bulb volume in order to achieve the required quality standards. Temperature variations during the shaping process may lead to variations in glass thickness and thus to variations in bulb volume. These variations may be caused by a variety of reasons, like changes of the calorific value of the gas, gas pressure, contamination of the burner and other implications. An easy way to overcome these problems is to measure the glass temperature during processing. Such a temperature control is ideally performed by infrared radiation pyrometry. The infrared radiation of the glass is measured and can be precisely related to its surface temperature. Using an infrared optic a defined spot on the glass surface can be measured. This paper looks at the LS12.42 line scanner from Heitronics.
