There are two methods used to perform the spiking. In the first, the scale method, a drum of material is placed on a scale, and a metering pump is used to inject the material either into the waste feed line or into a lance in the front wall of the incinerator. The weight on the scale is read periodically, and the amount of material spiked is calculated as the difference between the starting weight and the final weight on the scale.
The other method is the mass flow method whereby the material is pumped at a controlled rate through a precalibrated mass flow meter, and the data is saved to disk at 15-second intervals. A totalizer then computes the total mass of liquid added.
