| 摘要 |
<p>Apparatus for monitoring particles in a liquid by passing the liquid through an orifice disposed between two electrodes 1 includes an amplifier 22-27 of restricted bandwidth arranged to receive pulse signals from the electrodes on the passage of particles through the orifice, and a d.c. restorer circuit 29 coupled to the output of the amplifier and arranged to produce signals indicative of the amplitude of the pulses. The amplifier preferably comprises in series a high pass filter 22, a wideband amplifier 23, a high pass amplifier 25, a band-pass filter 26 and a low pass amplifier 27. The apparatus is able to monitor bacteria in urine using an orifice of 100 microns diameter and is capable of automatic and unattended operation.</p> |
