fig2 shows a blade section 10 checked according to the invention , reconstructed from its measured cartesian coordinates for a given height of the blade . because the blade is immobilized on the support , it is possible to define reference axes on this blade . the motor axis m represents the axis of rotation of the motor if the blade were installed on the rotor disk . the axis r represents a radial axis with respect to the axis of rotation of the motor . the axis t represents the tangential axis , normal to the two other axes m and r . the various points on a section of the blade 10 make it possible , by calculation , to determine the chord 14 and the centerline 11 of the blade . on an aerodynamic part , such as a blade or a wing , the chord 14 is the segment whose ends are the leading edge le and the trailing edge te , the leading edge le being the point most upstream on the blade profile with respect to a flow of air over this profile and the trailing edge te being the point most downstream on the blade profile with respect to a flow of air over this profile . the centerline 11 of the blade , also called the skeleton or mean camber line , is the set of points equidistant from the suction face 12 and from the pressure face 13 . all the parameters are calculated for a given blade section 10 . according to the method of the invention , a first checked parameter may be the angle of attack γ , that is to say the angle defined by the chord 14 of the blade and the motor axis m , as illustrated in fig2 . most of the distances involved in the parameters are calculated as reduced curvilinear abscissa on a curve which may , in the present invention , be the centerline 11 , the suction face 12 or the pressure face 13 of a blade section 10 . the curvilinear abscissa is reduced , which means that the length of the curve bounded by its two ends is dimensionless and that a distance , calculated on this curve starting from one of its ends , varies according to a scale from 0 to 1 . for reasons of simplicity , the distances are expressed as a percentage of the total length of the curve starting from one of its ends . a second checked parameter may be an angle β 1c formed by : a tangent at the point lc located along the centerline 11 at a distance corresponding to a percentage p of the total length of the centerline 11 starting from the leading edge le as curvilinear abscissa ; and the motor axis m , this percentage p must be between 1 % and 20 %, the optimum percentage p being 7 . 2 % as in the example shown in fig2 . it is unnecessary to check the parameters over the entire length . this is because it has been found that a parameter correct for this percentage p often implies that this parameter is correct over most of the length . an additional saving in time is therefore achieved by judiciously choosing the value of this percentage p . a third checked parameter may be an angle β ls formed by : a tangent to the point ls located along the suction face 12 at a distance corresponding to a percentage p of the total length of the suction face 12 starting from the leading edge le as curvilinear abscissa and the motor axis m , a fourth checked parameter may be an angle β lp formed by : a tangent to the point lp located along the pressure face 13 at a distance corresponding to a percentage p of the total length of the pressure face 13 starting from the leading edge le as curvilinear abscissa and the motor axis m , a fifth checked parameter may be an angle β tc formed by : a tangent to the point tc located along the centerline 11 at a distance corresponding to a percentage of the total length of the centerline 11 starting from the trailing edge tf as curvilinear abscissa and the motor axis m , a sixth checked parameter may be an angle β ts formed by : a tangent to the point ts located along the suction face 12 at a distance corresponding to a percentage p of the total length of the suction face 12 starting from the trailing edge te as curvilinear abscissa and the motor axis m , a seventh checked parameter may be an angle β tp formed by : a tangent to the point tp located along the pressure face 13 at a distance corresponding to a percentage p of the total length of the pressure face 13 starting from the trailing edge te as curvilinear abscissa and the motor axis m , several angles are defined to take into account the way in which the air flows while entering the blade near the leading edge . specifically , fig3 illustrates : β lc which is the blade entry angle on the centerline 11 , β ls which is the blade entry angle on the suction face 12 , and β lp which is the blade entry angle on the pressure face 13 . other angles are defined to take into account the way in which the air flows while exiting the blade near the trailing edge . specifically , fig4 illustrates : β tc which is the blade exit angle on the centerline 11 , β ts which is the blade exit angle on the suction face 12 , and β tp which is the blade exit angle on the pressure face 13 . an eighth checked parameter may be a thickness d l of the blade section 10 at a distance corresponding to a percentage p of the total length of the centerline 11 starting from the leading edge le as curvilinear abscissa , as illustrated in fig2 . the thickness d l is calculated along a segment perpendicular to the centerline 11 in the plane of the blade section 10 . a ninth checked parameter may be a thickness d t of the blade section 10 at a distance corresponding to a percentage p of the total length of the centerline 11 starting from the trailing edge te as curvilinear abscissa , as illustrated in fig2 . the thickness d t is calculated along a segment perpendicular to the centerline 11 in the plane of the blade section 10 . a tenth checked parameter may be a maximum thickness d max of the blade section 10 , as illustrated in fig2 . the thickness d max is calculated along a segment perpendicular to the centerline 11 in the plane of the blade section 10 , at the point on the centerline having the largest thickness of the blade section 10 . an eleventh checked parameter may be a value varβ lc representing the maximum difference between : the value of the angle β lc , at a distance corresponding to a percentage p 3 of the total length of the centerline 11 starting from the leading edge le as curvilinear abscissa , and the set of values of the angle β lc , ever a portion lying between a percentage p 1 and a percentage p 2 of the total length of the centerline 11 starting from the leading edge le as curvilinear abscissa , the value of p 3 being the average of the values of p 1 and p 2 . fig5 illustrates the intervals defined by the values p 1 and p 2 and the points p 3 . the method of calculating the angles involved is identical to the method of calculating the angles β lc , β ls , β lp , β tc , β ts and β tp . a twelfth checked parameter may be a value varβ ls representing the maximum difference between : the value of the angle β ls , at a distance corresponding to a percentage p 3 of the total length of the suction face 12 starting from the leading edge le as curvilinear abscissa , and the set of values of the angle β ls , over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the suction face 12 starting from the leading edge le as curvilinear abscissa , the value of p 3 being the average of the values of p 1 and p 2 . a thirteenth checked parameter may be a value varβ lp representing the maximum difference between : the value of the angle β lp , at a distance corresponding to a percentage p 3 of the total length of the pressure face 13 starting from the leading edge le as curvilinear abscissa , and the set of values of the angle β lp , over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the pressure face 13 starting from the leading edge le as curvilinear abscissa , the value of p 3 being the average of the values of p 1 and p 2 . a fourteenth checked parameter may be a value varβ tc representing the maximum difference between : the value of the angle β tc , at a distance corresponding to a percentage p 3 of the total length of the centerline 11 starting from the trailing edge te as curvilinear abscissa , and the set of values of the angle β tc , over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the centerline 11 starting from the trailing edge te as curvilinear abscissa , the value of p 3 being the average of the values of p 1 and p 2 . a fifteenth checked parameter may be a value varβ ts representing the maximum difference between : the value of the angle β ts , at a distance corresponding to a percentage p 3 of the total length of the suction face 12 starting from the trailing edge te as curvilinear abscissa , and the set of values of the angle β ts , over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the suction face 12 starting from the trailing edge te as curvilinear abscissa , the value of p 3 being the average of the values of p 1 and p 2 . a sixteenth checked parameter may be a value varβ tp representing the maximum difference between : the value of the angle β tp , at a distance corresponding to a percentage p 3 of the total length of the pressure face 13 starting from the trailing edge te as curvilinear abscissa , and the set of values of the angle β tp , over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the pressure face 13 starting from the trailing edge te as curvilinear abscissa , the value of p 3 being the average of the values of p 1 and p 2 . a seventeenth checked parameter may be a value avβ lc representing the average value of the angle β lc over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the centerline 11 starting from the leading edge le as curvilinear abscissa . an eighteenth checked parameter may be a value avβ ls representing the average value of the angle β ls over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the suction face 12 starting from the leading edge le as curvilinear abscissa . a nineteenth checked parameter may be a value avβ lp representing the average value of the angle β lp over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the pressure face 13 starting from the leading edge le as curvilinear abscissa . a twentieth checked parameter may be the value avβ tc representing the average value of the angle β tc over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the centerline 11 starting from the trailing edge te as curvilinear abscissa . a twenty - first checked parameter may be a value avβ ts representing the average value of the angle β ts over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the suction face 12 starting from the trailing edge te as curvilinear abscissa . a twenty - second checked parameter may be a value avβ tp representing the average value of the angle β tp over a portion lying between a percentage p 1 and a percentage p 2 of the total length of the pressure face 13 starting from the trailing edge te as curvilinear abscissa . the values p 1 and p 2 fall within the [ 1 %- 20 %] interval . it is preferable for this interval to relate to a portion representative of the centerline , of the suction face or of the pressure face essentially upstream of the point lc , ls or lp relative to the direction of flow of the air . likewise , it is also preferable for this interval to relate to a portion representative of the centerline , of the suction face or of the pressure face essentially downstream of the point tc , ts or tp with respect to the direction of flow of the air . the [ 7 %- 13 %] interval makes it possible to obtain significant results , allowing a greater precision of the checked parameter . in order to check the turbomachine blades , it is possible to combine a check taking into account the aerodynamic parameters defined above with a conventional check of the prior art . according to a preferred method of implementing the invention , several aerodynamic parameters are chosen simultaneously to check the blade , these parameters being the angle of attack γ , the angle β lc , the angle β ls , the angle β tc , the angle β ts , the thickness d l , the thickness d t , the thickness d max , varβ lc , varβ ls and varβ ts of the blade section 10 . this selection of more relevant parameters makes it possible to limit the number of parameters so as to make them more easily exploitable . moreover , it has been found that the validity of these parameters implies , quite systematically , the validity of the entire blade section 10 . the following table illustrates examples of parameters for a given blade section and also the tolerance associated with each parameter . each nominal aerodynamic parameter defines , with its associated tolerance , a validity range within which the measured aerodynamic parameter must lie in order to validate the blade . when the measured aerodynamic parameter does not lie within this validity range , the measured blade is rejected . if a plurality of aerodynamic parameters are taken into consideration in the method , an aerodynamic parameter not lying within its corresponding validity range would entail rejection of the blade . all of the chosen parameters must be valid in order for the checked blade to be validated . these parameters may be calculated for a plurality of sections of a checked blade , each of the sections having separate nominal parameters . however , it may be judicious to take into account a limited number of sections . this is because it has been found that the fact of selecting and checking three sections located near the base , in the middle and near the tip of a blade , respectively , is sufficient to have an idea of the overall validity of the blade . a section located near the base may be a section lying between 0 % and 30 % of the height of a blade . a section located near the middle may be a section lying between 30 % and 70 % of the height of a blade . a section located near the tip may be a section lying between 70 % and 100 % of the height of a blade . preferably , the three sections are located at 10 %, 50 % and 90 % respectively , of the height of the blade , as illustrated in fig6 . a blade , the sections 10 of which at 10 %, 50 % and 90 % of its height meet the criteria according to the invention , has , quite systematically , sections that are valid over its entire height . conversely , a blade in which one of the three sections 10 does not meet the criteria described above has , quite systematically , a plurality of incorrect sections over its entire height . an additional time saving is therefore achieved by judiciously choosing significant sections . the method according to the invention makes it possible to save a considerable amount of time in checking the blades , especially after their manufacture . the processing corresponding to each step of the method , especially the calculations of the various parameters , may advantageously be implemented by a computer program organized in modules 24 , 25 , 26 and 27 , each module carrying out one step of the checking method . the invention also relates to a system for checking turbomachine blades , comprising means 21 for measuring the geometrical coordinates of a plurality of points on a blade 20 to be checked , and a means 23 for the processing of a computer program intended to implement the method of checking turbomachine blades . such a system is illustrated in fig7 , in which the measurement means 21 may be a measurement means known from the prior art . the means 23 for processing a computer program may be a computer which includes a memory in which the computer program intended to implement the method of checking turbomachine blades according to the invention is stored . the system for checking turbomachine blades designed to implement the method of checking turbomachine blades according to the invention essentially comprises the following means : means 21 and 24 for measuring the geometrical coordinates of a plurality of points on a checked blade 20 ; a means 25 of calculating the aerodynamic parameters of the measured blade 20 ; a means 26 of verifying the validity of the measured parameters with the nominal parameters and their associated tolerances of a reference blade 22 ; and a means 27 of validating or rejecting the checked blade 20 .