Spectro Midex Micro-XRF Elemental Analyser for Rapid Point Analyses and Mappings

SPECTRO Analytical Instruments introduced the third generation of the SPECTRO MIDEX micro XRF spectrometer at the 2009 Pittcon Conference in Chicago (March 8 to 13, 2009). The latest version of the SPECTRO MIDEX incorporates a number of improvements that make it faster, more powerful and easier to use than its predecessor. The versatile instrument has been designed particularly for the electric and electronics industries, precious metals market, automotive and aviation industries, and forensic laboratories.

The SPECTRO MIDEX micro-XRF analyzer is equipped with an air-cooled low-power X-ray tube with micro focus. The spectrometer utilizes software controlled collimated point excitation. The size of the measuring spot can be optionally set in steps between 200 micrometers and 4 millimeters. The current model, which combines the formerly separate MIDEX and MIDEX M versions, utilizes the latest generation silicon drift detector that processes up to 250,000 pulses per second.

“The new detector makes the MIDEX even faster. It is able to scan the microelectronics on an EK board, a standard size for printed boards, in 30 minutes” explains Dirk Wissmann, SPECTRO Product Manager for XRF spectrometers. “During point analyses, the MIDEX determines the entire contents of a sample in two minutes. Additionally, the stronger detector delivers exact results even with a working distance of 20 millimeters from the sample.”

“The latest version of the SPECTRO MIDEX opens new areas of use. We can examine components of varying heights on a mounted printed board without damaging the board. And, it’s just as easy to non-destructively search for inclusions in finished automotive components,” notes Wissman.

Motor- Driven Sample Plate
The MIDEX has a sample chamber that may be optionally equipped with a motor- driven XYZ table. For mapping analyses, the travel path can be freely programmed along a surface of 240 x 178 millimeters. For example users are able examine all of the capacitors on an electronics board.
“Users also like to use the XYZ table as an autosampler. They place several samples on the table and then program the travel path so that all of the samples are examined. SPECTRO equipped the sample chamber with an integrated video system for point measurements. Users can exactly set the measuring spot and even document the analyzed point in a video image,” explains Wissmann.

Analyzes Surfaces and Valleys
Marketing Director Tom Milner sees two large markets for the SPECTRO MIDEX. “With its strong mapping features and the option of scanning to a depth of 20 millimeters, the MIDEX will set new standards for RoHS compliance screening,” he predicts. “A second important market is the jewelry and precious metal industry.”

The MIDEX also has application within the automotive and aviation industries, where it can search out inclusions in glass and metal samples, and in forensics to view powder burns using X-ray fluorescence.

The new MIDEX supports two types of operation. With the standard configuration, the distance between the excitation source and the measuring spot is two millimeters. This mode is well suited to rapid point measurements such as testing precious metal alloys as well as line scans and mappings of flat surfaces with a large measuring spot. This configuration can be supplemented using an optional helium flush that enables the MIDEX to measure the light elements from magnesium to titanium.

As an alternative, the MIDEX can be configured so that the distance between the excitation source and the measuring spot is 20 millimeters. This distance is ideal for the non-destructive analysis of the lower lying components on a sample. Three- dimensional topologies such as especially high boards or pieces of jewelry with structured surfaces can be easily analyzed.
“The MIDEX always was ideal for the non-destructive analysis of expensive jewelry and artwork. Now, the instrument has become even faster, which means a vast time savings especially for elaborately structured and massively sized pieces,” comments Milner.