Components of a Flame Photometer

Components of a Flame Photometer

In a Flame Photometer there are 5 main components that make up the instrument. These are:

1) Flame

2) Nebulizer

3) Mixing Chamber

4) Colour Filters

5) Photo Detector

The Flame (Burner)

A flame photometer needs a flame that can be maintained in a constant form and at a constant temperature. The burner head combines the mixture of gas, air and vapour sample into an emission spectra from a flame burning at approximately 1900 degrees Celsius. The burner assembly must not only warm up rapidly and maintain a constant temperature, but also ensure that gas velocities and burn rate are controlled so that the blowback of the flame cannot occur, ensuring safe operation. Most instruments include a viewing port allowing the operator to observe the flame conditions and set the height of flame. The BWB burner assembly is constructed from high performance grade stainless steel and expertly machined to high tolerances using CNC lathes.

Nebuliser and Mixing Chamber

The nebuliser is a small-bore needle through which a liquid sample is drawn and consumed. A jacket of high-pressure air passes around the needle, drawing the sample up and atomising it into a fine mist. Obtaining a fine mist is essential to the instrument's accuracy and is the heart of its repeatability, accuracy, and stability.

After atomisation, the sample passes into the mixing chamber, where the fuel gas is mixed into the sample mist. A cyclone action thoroughly mixes the gases, which avoids hot spots of higher fuel concentration that would cause greater and random emissions in the flame, affecting stability and repeatability.

Colour Filters

The colour filters show us which metals are present. Photodiodes cover a large range of wavelengths, so to ensure only the required wavelength is collected they are installed behind an interference filter, produced to only allow a specific range of light to pass through, with minimal spectral overlap between different ions' spectral emissions.

Photo Detector

The photo detector tells us which metal the sample contains and to what concentration level. Once the light has been converted to an electrical signal, it needs displaying in a form appropriate for user interpretation. Older flame photometers display this as a number for the operator to plot on their own calibration curve, or as a concentration relative to a pre-generated calibration curve. At BWB, we not only display it as a number to give the user transparency, but also capture, save and store the calibration details and provide direct display for sample analysis.

Calibration and Microprocessor Control

BWB's range of flame photometers are microprocessor-controlled. The BWB XP Plus allows the operator to produce self-defined calibration curves across the 4 detectable elements, with up to 10 calibration points per ion. All 4 elements can be calibrated simultaneously using multi-ion calibration standards, drastically reducing operation time. 

Microprocessor technology allows the XP Plus to adjust the calibration curve automatically, making allowances for changes in atmospheric conditions or sample temperature through the use of an internal standard, which can be Lithium or the fifth channel of operation, Caesium.

Please contact us for more information on the range of BWB Technologies flame photometers.