Kistler North America, a worldwide supplier of precision sensors, systems and instrumentation for the dynamic measurement of pressure, force, torque and acceleration, has introduced the Type 5155A multi-channel temperature and pressure charge amplifier. The Type 5155A is expressly designed to convert the charge signal from all types of piezoelectric sensors and Type K thermocouples into a proportional voltage output signal, for the effective monitor, control and optimization of injection molding processes. 

Offered in two measurement ranges, with choice of single, two- or four-channel operation, Kistler Type 5155A measurement range inputs may be switched over individually for each channel by remote control. Amplifiers equipped with temperature inputs are provided with one charge amplifier unit and one temperature amplifier, or two charge amplifiers and two temperature amplifiers, in a rugged case with IP65 rated sealing. At the input of all charge amplifier modules is a capacitive negative feedback amplifier, featuring a hybrid design with extremely high insulation resistance. A differential input circuit ensures that common-mode signals of ±4V between sensor/low and output/power ground, such as those found in industrial environments, have no disturbing influence.For thermoplastic injection molding, Type 5155A offers a special SmartAmp "self-optimizing switch-over detection" option, easily integrated into machinery control systems, which automatically detects volumetric filling of the mold based upon pressure. Within each cycle, the "SmartAmp" sends a control signal to the injection molding machine while automatically compensating for process fluctuations, thereby producing moldings with greater uniformity. This option considerably reduces set-up time, since the switching point is automatically preset by means of the charge amplifier, without the need for manual optimization. Design of the Kistler Type 5155A also allows for the use of piezoelectric sensors without a piezo adapter, further saving costs. The charge amplifier is suitable for optical lens manufacturing, thin- or thick-wall medical component molding, and electrical connector manufacturing applications.