In order to measure accurately water-pastern ratio of cement fly ash grout in grouting engineering

an unclear device of measuring water-pastern ratio is designed.It is based on γ-rays weakening characteristic when γ-rays go through cement fly ash grout

weakening amount is relative to grout densit.When rays intensity

ray-locator and cement fly ash gout thickness are defined

the grout density and water pastern ratio can be calculated by mathematics model.Experiment results show that the device has the characteristics of good stability

high precision and sensitivity

quick response and so on

and it can work normally under high temperature

damp and dust environment.