The pressure module series KTN enables measuring pressure difference, but not on high static pressure. If only one of the pressure inputs is connected, it is also possible to measure relative overpressure or underpressure against the surrounding atmosphere. These modules can also be supplied made-to-order for measuring absolute pressure.
By means of these modules it is also possible to measure very low pressure differences, which predetermines them for use in the area of ventilation and air-conditioning control, combustion process control, monitoring of working conditions in laboratories, pure spaces, etc. The measured medium can only be non-aggressive gas.
The pressure is connected by means of plastic tubes with the internal diameter 5 mm to inlets from nickel coated brass. These inlets do not serve for mechanical fixing of the module. The measured medium is in direct contact with the silicon measuring membrane. Besides the above mentioned materials, this medium is in contact with plastic material polyetherimid and fluorine-silicon sealing.
The module is intended especially for instrument construction. It is delivered in the form of a fitted plate for brazing into the user´s printed circuit by means of gilded pins which also serve for electric connection. The plate itself is varnished but has neither electric nor mechanical cover and thus protection of the final product construction is supposed.
At this type of module, pressure is
measured by means of a sensor with a silicon membrane, the measuring principle is piezoelectric. Thanks to this, the module achieves high overload capacity, it is resistant against vibrations and can work in any position. Ann undisputable advantage for some applications is the possibility of measuring both underpressure and overpressure by one module. The electronics is realized by surface mounting technology.
Electric signal from the pressure sensor is strengthened, compensated, calibrated and transferred to the output voltage. The standard output range is 0÷10 V. At an agreement it is also possible to adjust a different range of the output voltage or make modules with the current output 4-20mA or 0-20mAA. Modules can be fed from a direct-current supplies with voltage in the range 12-36V without any influence on the measuring accuracy. Calibration of the measuring range is fixed, fine adjusting (ca. by 3%) of the end points of the transfer characteristic is possible by means of multi-revolution trimers. The trimer for adjusting the range beginning (zero) is marked Uo, the trimer for adjusting the range is marked FS. Short-circuit couplings for choosing the dumping time constant are also accessible on the module.
We recommend using standardized pressure ranges, but based on an agreement it is possible to adjust any range in the range of nominal pressures and outputs, including symmetric and asymmetric combinations underpressure-overpressure.
