Environmental Dependence of the Performance of Resistive Plate Chambers

This paper reports on the performance of Resistive Plate Chambers (RPCs) as function of the gas flow rate through the chambers and of environmental conditions, such as atmospheric pressure, ambient temperature and air humidity. The chambers are read out by pads with an area of 1 x 1 cm2 and a 1-bit resolution per pad. The performance measures include the noise rate as well as the detection efficiency and pad multiplicity for cosmic rays. The measurements extended over a period of almost one year and are sensitive to possible long-term aging effects.