crescograph
/ˈkrɛskroʊɡræf/Definitions
1. noun
An instrument used to measure the rate of growth or change in the amplitude of sound waves.
“The musician used a crescograph to analyze the dynamics of the symphony.”
2. noun
A device for measuring the rate of change or growth in a physical quantity.
“Researchers used a crescograph to monitor the increase in the population of the endangered species.”