CNS Lab: Standard automation for combustion analysis

CNSLab

The HERZOG CNSLab is the fully-automatic solution for elemental analysis of solid materials by furnace combustion. The CNSLab has been specially developed for the analysis of iron and steel samples using punched pieces or milling chips, but it can also be used for other types of inorganic materials.

The CNSLab covers the complete process of sample preparation from the automatic receiving of the sample up to the transfer of the preheated crucible containing the weighed sample and additives to the analyser. Furthermore, the CNSLab supports all steps required for instrument calibration including management of reference samples and the definition of the calibration procedure.

According to the sample volume, the CNS Lab may have one robot with up to two analysers or two robots with up to four analysers. In the latter case, the CNSLab ensures system availability if one robot is in service mode. In each case, the analyzers are rotatable in the housing and can be turned around for manual operation. In this operation mode, the robot access to the analysers is automatically locked because for safety reasons.

The CNSLab offers many opportunities. It leads to a significant reduction of mundane tasks for the laboratory personnel, increases sample throughput and improves the quality of sample preparation and analysis.

Automatic receiving of samples

The production samples can be automatically received from the pre-stage sample preparation cell. In this case, the samples are transported from the sample preparation machine to the CNSLab by a pneumatic tube system. Solid pieces are usually punched out of double-thickness or disc samples using the automatic punching machine HUST. From here, up to four punched pieces are transferred separately to the receiving unit of the CNSLab. Furthermore, milling chips can be used for analysis after automatic capture in the milling machine and transportation to the CNSLab. The PrepMaster control software of the CNSLab takes care of sample management, sample ID shifting and communication with the analysing instrument.

Alternatively, samples can be introduced manually by the operator. In this case, the operator registers the sample by using the keyboard or integrated touch panel (option) and inserts the material via a special input drawer.

Tailored solutions for all analytical requirements

The CNSLab performs all sample preparation steps necessary for successful and reliable combustion analysis. A multi-axis robot carries out the handling of samples and crucibles, providing maximum flexibility and processing speed. The modular software-design of the PrepMaster allows easy adaptation of worksheets and sample routing according to the requirement of each customer.

Batches of new crucibles (standard ceramic or graphite crucibles) are easily supplied to the system by insirting trays via input drawers. Ceramic crucibles are automatically preheated in a special through-type tube furnace. The PrepMaster takes care that each crucible is held for a given amount of time at the required temperature. If a crucible at the output position of the furnace exceeds the acceptable cool-down time it is automatically transferred to the input position for re-heating.

After the arrival of the punched piece in the receiving unit the sequence of process steps depends on the intended analysis. For CS analysis, the robot takes the ceramic crucible from the pre-heating furnace and transfers it to a high-precision balance for determination of the tare weight. Then the robot fills the sample into the crucible and the exact sample weight is determined which is used by the analyser. Subsequently, the crucible with the sample can be annealed to temperatures up to 800°C by an induction heating unit (option). This removes undesirable carbon deposits that could potentially contaminate the surface of the sample. Afterward, the robot transfers the crucible to the dosing unit for additives and a pre-defined amount of accelerator is released on top of the sample. Eventually, the crucible is placed on the furnace pedestal of the CS analyser and the analysis is initiated.

For ONH analysis, the robot transfers a new graphite crucible from the input tray to the lower electrode of the analyser. Then the aluminium cup from the receiving unit is weighed together with the sample and inserted into the loading head of the analyser. Afterward, the empty aluminium cup is weighed again to calculate the precise sample weight which is forwarded to the analyser.

Instrument calibration with many options

Reference and calibration/drift samples are stored in a special rack magazine with up to 70 positions. The magazine is readily accessible by opening the safety door and can be easily loaded by the operator. The PrepMaster makes registering new reference samples very simple and provides a fast overview of all reference materials in the system.

For the management of calibration analyses, different options are available. The PrepMaster may regularly notify the operator, which then selects appropriate reference samples and starts the calibration manually. Alternatively, the operator defines calibration plans and PrepMaster initiates the calibration process automatically.

PrepMaster control system for smooth operation

The PrepMaster control system ensures the smooth operation of the CNSLab. It provides the operator with a fast overview of all relevant data, including production and reference samples within the system, the state of the preheated crucible, load of analysers etc. Intelligent registration procedures make it easy to insert crucibles and samples, no matter if you use a keyboard or touchscreen as an input device. Furthermore, PrepMaster guarantees a seamless integration of the CNSLab with other automation sections and analysers.