Analysis of Steel and Iron with ARL easySpark Optical Emission Spectrometer

For more than 80 years, the company has established the standard of quality for optical emission spectrometers used for the analysis of metals. Performance, reliability and stability have been the major attributes of the instruments, usually designed for metals producers and labs. The Thermo Scientific™ ARL easySpark™ metals analyzer continues this tradition of experience and technical innovation in order to provide the best value-based solution to customers.

easySpark Optical Emission Spectrometer

The ARL easySpark is capable of determining all the elements necessary in the current and future applications, in all possible qualities of steel and iron: white or grey cast iron, alloyed cast iron, high alloy steel and low alloy steel. It is the answer to the analytical requirements, whether for incoming goods control, process QC, final product QC, certification, metal sorting or investigation. With maximum uptime, the ARL easySpark metals analyzer delivers dependable performance consecutively every year.

easySpark Optical Emission Spectrometer

ARL easySpark - Revolution in Benchtop OES

The ARL easySpark is a compact bench-top spectrometer based on an innovative multi grating/CCD optical design operated under argon environment at controlled temperature. It offers full elemental coverage, stability and optimal resolution, and offers high performance for all the critical elements.

The ARL easySpark benefits also from the same improved features earlier used in larger floor standing instruments of the Thermo Scientific OES product line, among which:

  • Advanced CCD signal acquisition and processing for enhanced accuracy and performance
  • Compact version of the intelliSource, a digital spark source with increased efficiency and flexibility
  • Spark stand with optimal operator safety and minimize argon consumption during the analysis
  • ECOmode and super ECOmode allowing significant argon savings when the instrument is idle
  • Optimal design increasing the instrument functionality

Innovative CCD Optical System

On the ARL easySpark the new multi grating/CCD optics allows a continuous spectral coverage combining optimal performance for every element as well as high flexibility for spectral examinations or future applications. It features a high-class UV resistant CCD detector that has been developed specially for spark/arc OES and whose temperature is controlled by means of Peltier cooling device to guarantee the best precision and stability.

IntelliSource Digital Spark Source

The compact version of the patented Thermo Scientific intelliSource is referred to as a double current controlled source (CCS), the most innovative excitation source for Spark OES. It allows discharge shapes to be customized for most efficient control of the sample surface preparation, material ablation and light emission in different metal matrices.

Matrix-optimized pre-integration sparks greatly reduce the effects of matrix and metallurgical structure (in re-melting the sample surface before the integration spark), which enhances the accuracy of the analysis.

Other innovative features contribute to the performance of the intelliSource, for example, Discharge Interrupt by Short-Circuit (DISC) that enhances the repeatability in trace analysis.

CCD Signal Acquisition and Processing

Varied techniques and methods are applied in order to enhance performance with the CCD of the ARL easySpark like automatic dynamic dark current subtraction to improve the signal to noise ratio. Spectrum alignment and digital resolution enhancement are also carried out automatically during every acquisition in order to improve precision, long-term stability and accuracy.

Sample Preparation

Generally, the sample is prepared by using a grinding machine (for example, stone grinding for cast irons and paper for steels).

Performance Guarantee

The company guarantees the precision, which expresses the closeness of the concentration values of the individual runs of an analysis. The lowest the precision value, the smallest the number of runs required for high confidence in the average result.

Accuracy and Factory Calibration

The accuracy is the most vital figure of merit of a spectrometer. It states the agreement between the reference value and the result. It relies on the quality of the reference materials employed for calibration, on some instrumental attributes (for example, the optical resolution, the spark source condition) and on the mathematical model employed for calculating the calibration curves. The calibrations are carried out using carefully tested and well accepted certified reference materials (CRMs) and reference materials (RMs). The calibration curves are established using an extremely sophisticated multi-variable regression (MVR) software tool that is capable of correcting matrix effects, spectral interferences and guarantees the highest possible accuracy.

Calibration Summary

The following calibrations are available for cast irons and steels:

  • Low Alloy Steel
  • Manganese Steel (Mn ≤ 20 %)
  • High Speed Steel (Co ≤ 10%)
  • Nickel Resist (Ni ≤ 35 %)
  • Free Cutting Steel (with S and Pb ≤ 0.3 %)
  • Chrome Steel (ferritic stainless steel)
  • Cast Iron - including nodular iron and Ni-hard (Ni ≤ 7 %)
  • High Alloy Cast Iron (Cr ≤ 32 % and Ni ≤ 16 %)
  • Chrome-Nickel Steel (austenitic stainless steel)
  • Global Iron (including all qualities except for free cutting steel)

The calibrations are delivered as turn-key, completely parameterized applications along with setting-up samples (SUS) in order to maintain the accuracy of the calibration.

The measurement uncertainty can be displayed for each sample based on the calibration curves and the repeatability of the measurements.


Stability of the instrument is of extreme importance when carrying out routine analysis. High stability decreases the frequency for maintenance and drift correction operations.

The examples below demonstrate the long-term stability of nickel in a stainless steel sample and carbon in a cast iron sample recorded over a period of five days without any intermediate drift correction. No standardization was needed, as the measured concentrations stayed within an interval of +/- 2 times the ensured precision value, which is considered to be excellent.

Memory Effects

The memory effect is defined as the number of runs essential for reducing the measured concentration to the expected one after examining high alloyed samples, such as stainless steels. The ARL easySpark is capable of accurately measuring trace elements after five runs.


The ARL easySpark is a compact, desktop spectrometer ideal for metals analysis, based on new CCD technology, which offers flexibility for the analysis. It can be installed and also used on the same day it is delivered. Easy to handle, the ARL easySpark provides precise, reliable and quick analysis.

Its accuracy, linked with its excellent reliability and stability allows for results to be obtained that one can rely on 24 hours a day, 365 days a year without spending too much time in expensive and long lasting drift corrections.

Additionally, the ARL easySpark offers the following advantages:

  • Unique safe open stand
  • New icon based easyOXSAS software
  • Extensive range of metals analysis
  • Advanced technical/service support
  • Easy and simple to use and maintain by an unskilled operator
  • Low consumption of drift correction samples and simple maintenance

All these features allow users to optimize their productivity and achieve the shortest payback times:

  • Investment costs are decreased by:
    • Exceptional instrument lifetime and continuous upgrade possibilities (hardware and software)
    • Instrument capability to cover future requirements
  • Production costs are reduced by:
    • More accurate and reproducible analyzes made available faster
    • Increased instrument availability thanks to its great stability and less frequently needed drift corrections
  • Operating and maintenance costs are reduced by:
    • Significant argon savings during analysis and in stand-by
    • Low consumption of drift correction samples and simple maintenance
  • Overall cost management is reduced by:
    • Extremely low running costs compared to other methods
    • Optimum utilization of materials

For more information on this source and to obtain typical precision tables, please visit Thermo Fisher Scientific - Elemental Analyzers.

Thermo Fisher Scientific

This information has been sourced, reviewed and adapted from materials provided by Thermo Fisher Scientific - Elemental Analyzers.

For more information on this source, please visit Thermo Fisher Scientific - Elemental Analyzers.

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