Abstract: A frame has sensors mounted thereon for engaging selected portions of a sand core and generating signals proportional to sensed dimensions of the sand core. A control unit compares the sensor signals with a zero reference dimension and a dimensional tolerance range for each sensed dimension of the sand core and generates an indication of acceptable/unacceptable core dimensions. A computer monitor and/or light panel is activated by the control unit and provides a visual indication for each sensed dimension by means of numeric data, color, directional arrows or distinct illuminated lights of an acceptable/unacceptable and even a marginally acceptable sand core.