Abstract: A process provides for measuring particles in suspension in a liquid in an particle response analyzing instrument comprising a cytometric flow cell head, wherein the suspension is injected into the head at an injection rate, the head comprises one or several sensors which deliver responses when measuring particles injected therein and which yield a significant response for a set measurement frequency range. The response is processed and used to generate results in the instrument. When a first response is significant, measurements continue at the same injection rate in order to obtain a result thats likely to continue being a significant response during subsequent measurements and, conversely, when the first response is not significant, the injection rate is modified in order to bring the response within a significant response range and to continue with measurements in order to obtain a result.