THE MEASURABILITY OF THE GRAVITATIONAL FIELD IS DISCUSSED FROM BOTH THE CLASSICALLY SUCH A MEASUREMENT CAN BE PERFORMED IF ONE USES TEST BODIES WITH VANISHING SMALL MASS. ON THE OTHER HAND, DUE TO THE HEISENBERG UNCERTAINTY PRINCIPLE, IT IS FOUND THAT ONE MUST USE TEST BODIES OF EXTREMELY LARGE MASS IN ORDER TO OBTAIN ACCURATE RESULTS. THUS IT APPEARS THAT AN ACCURATE DETERMINATION OF THE GRAVITATIONAL FIELD IS NOT POSSIBLE IF ONE TAKES INTO ACCOUNT THE QUANTUM RESTRICTIONS. CONSEQUENCES OF THIS RESULT WILL BE DISCUSSED.