In an amplifier with pass-through mode of the present invention, in a pass-through mode, a signal transmission transistor and a bias control transistor are turned ON and a voltage of an output terminal is maintained in a ground potential via the bias control transistor and a resistor. The methods utilize measurements of background radiation in two spectral regions of interest to calculate a normalization constant, and then utilize the normalization constant to normalize measurements in the same regions of interest when a vehicle or container is tested for the presence of a relevant ionizing radiation source such as 137Cs and 76Ga. A memory page containing the location of a breakpoint is copied to a temporary memory page. In this way, different splits of, for example, an eight bit WID may be obtained based on the setting of the programmable WAT color size selection device such that varying color and overlay capabilities are obtainable dynamically. A continuous spray system provides a spray of dilute caustic solution in a selected spray configuration for mass transfer contact with the passing intermediate purity water vapor stream, to remove volatile silica compounds therefrom, and produce a partially decontaminated steam stream having mist particles therein. The RMMA space is mapped to a free portion of a system memory address space of the remote processor.