Ammeter a digital voltmeter, through use of an analog to digital converter (ADC); the digital display is calibrated to display the current through the shunt. Such instruments are often calibrated to indicate the RMS value for a sine wave only, but many designs will indicate true RMS within limitations of the wave crest factor. There is also a range of devices referred to as integrating ammeters. In these ammeters the current is summed over time, giving as a result the product of current and time; which is proportional to the electrical charge transferred with that current. These can be used for
Coal Measures Group the: In South Wales, the larger part of what had been the Upper Coal Measures now forms the Pennant Sandstone Formation in the overlying Warwickshire Group. The South Wales Coal Measures Group is preceded (underlain) by the Marros Group. Coal Measures Group The Coal Measures Group is a lithostratigraphical term coined to refer to the coal-bearing succession of rock strata which occur in the United Kingdom within the Westphalian Stage of the Carboniferous Period. Other than in Northern Ireland the term is now obsolete in formal use and is replaced by the Pennine Coal Measures Group, Scottish Coal Measures Group