Volumetric Verification

Keywords Laser tracker, volumetric verification, geometrical errors, regression functions, kinematic model. 

Abstract. This paper aims to present different methods of volumetric verification in long range machine toll with lineal and rotary axes using a commercial laser tracker as measurement system. 

This paper presents the kinematic model of several machine tools with different kinematic chains use to improve the machine tool accuracy of each one by volumetric verification. Likewise, the paper thus presents a study of the adequacy of different nonlinear optimization strategies depending on the type of axis and the usable space available. 

Volumetric verification consists of minimizing the difference between real points and theoretical points which are introduced for numerical control (NC) (Fig. 1). Theoretical points are introduced as trajectory, mesh or cloud of points depending on the possibilities and necessity of the technique employed. The determination of the technique depends on the sequence of movements and the errors that affect to the MT, structure and type of the machine. 

Fig. 1 Operation scheme of volumetric verification using laser tracker as measurement system...

To simplify the study of volumetric verification strategy in multi-axis machine tool, the geometric configuration of the machine from which this work has been realized, corresponds to a grinder XCFZ (Fig. 3). 

Volumetric error reduction depends on polynomial regression functions used to characterize the geometric errors To realise a proper volumetric verification of any machine tool with rotational axes, such as XCFZ, it is necessary to obtain the approximation functions of each of the errors of a rotational axis, as well as approximation functions of lineal ones. 

To tackle the volumetric verification of a machine with linear and rotational axis XCFZ, the method of optimization is extended in comparison with the methods for machines with three linear axe [5, 6]. 

Joint optimization of the errors from linear and rotational axis. The use of joint optimization as a technique of volumetric verification requires that a plane of point XY could be measured in different positions of C axis (Fig.5 A). This plane is limited either by the housings for the protection of the machine or by the structure of the same, leaving limited the volume of the machine used in the verification (Fig. 5 C or F ig. 5 B). 

General principles of calibration of course apply to speciation analysis (Griepink, 1993 Quevauviller et al., 1996a). All efforts made to obtain a good sample and perform the extraction under the proper conditions are spoiled if the calibration is wrong. Basic principles of QA apply here, including calibration of balance and volumetric glassware, verification of the calibrant purity and stoichiometry, verification of the stability of stock solutions, etc. 

Prepare the calibration standards by pipetting 0- (this is called the reagent blank), 1-, 2-, 3-, 4-, and 5-mL aliquots (portion thereof) of the 100 ppm Fe stock solution into a 100-mL volumetric flask. Also prepare an instrument calibration verification (ICV) standard by pipetting 2.5 mL of the 100-ppm Fe stock solution into a 100-mL volumetric flask. Measure the ICV s absorbance after developing the color below in triplicate. The ICV is used to evaluate the precision and accuracy of any instrumental method via interpolation of the calibration curve and is essential to maintain-... 

Volumetric feeders offer no verification of the feed rate and permit no simple means to record their historic performance. Apart from an ongoing certification of performance, registered measurable values allow alarms to be actuated and failsafe or corrective action to be automatically engaged, should the feed rate fall outside acceptable limits. 

Machine tool geometric error identification strategy depends on the type and configuration of the machine as well as the purpose of verification [5, 6].The difference between theoretical and real point represents the influence combined of machine errors for each point, volumetric error (ve) Eq, 1. Minimizing the machine tool volumetric error using non-lineal optimization techniques, the approximation functions of each error can be obtained, if there are enough measured points. 

When temperature equilibrium is obtained, 2 ml of amine-H20-C02 was injected into 85% of phosphoric acid solution present in the reactor flask. The esterification reaction occurred and CO2 was released with N2 flow through the condenser and the condenser would condense evaporated water. Then, CO2 goes into an infrared analyzer and the software connected with the infrared show the amount of CO2 in % (peak) over the time. Experiment was repeated three time for verification of the amount of CO2 loading. For each peak, the determination of CO2 volumetric flow, based from CO2 vol% determinate by software, was calculated as below ... 

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