P037 A FAST CALIBRATION PROCEDURE TO ASSESS THE RELIABILITY OF HEAT PULSE FLOW METER MEASUREMENTS INTRODUCTION 1 The heat pulse flow meter allows the measurements of vertical distribution of hydraulic conductivity in an aquifer. On this purpose the probe is calibrated and calibration coefficients are entered into processing software to determine vertical flow rates in liters/minute or m 3 /sec. However these coefficients may vary with time. This paper presents a way of determining these coefficients by means of a laboratory based “borehole” apparatus. The resulting values may be used to more confidently calculate vertical flow rates in boreholes. THEORY