Panel digital meters Sch20, Sch21, Sch22, Sch23 are intended to measure current or voltage in DC circuits (for operation as part of technical means of nuclear power stations (NPP TM) and in other sectors of thhe industry). The meters could be used complete with primary transducers for measurement non-electrical values if ranges of output electrical signal of primary transducers corresponds to the meters input signal ranges. Input signal measurement ranges: 0–5 mA; 0–20 mA; 4–20 mA; 0–75 mV; 0–200 mV; 0–1 V; 0–10 V; 2–10 V. The meters are powered from the DC source of (24 ± 4) V. In this case double pulsation amplitude shall not exceed 1.2 V. Under climatic conditions the meters belong to articles of TV4.1 design (with expansion of Temperature range (operating) minus 10 to plus 50 °С) intended for operation in the atmosphere of type III according to GOST 15150-69. The meters meets the requirements for electromagnetic compatibility according to GOST R 50746-2000 imposed to group IV of NPP TM (technical means supplied to nuclear power stations and/or radiation hazardous facilities). A level of industrial interferences when operating meters does not exceed values preset by GOST 30805.22-2013 for equipment of class B. For the level of protection against effect of solid bodies, the meters meet IP code according to GOST 14254-96. Mean time between failures is 150000 hours min. The meters service life is at least 15 years. All meters are made in a metal case and fire-proof, have no mobile parts and provides resistance to mechanical effects according to group М40, seismic resistance of 9 points provided installation above zero position up to 10 m, 8 points at the installation level of up to 25 m according to GOST 17516.1-90, belong to category I of seismic resistance according to NP-031-01. The meters are made in a metal case with panel fastening. The fastening design is rated for installation in the panel of 50 mm in thickness. According to the order, installation is possible in a panel with other thickness. The meters intended for NPP may be used in the security system and systems of normal operation; depending on the order they meet safety classes 2, 3, 4 and have classification designation 2NU, 3NU according to OPB-88/97 NP-001-97. Working conditions of operation: – ambient air temperature of minus 10 to plus 50 °С; – relative air humidity of 98 % max. at plus 35 °С; – atmospheric pressure is 84...106.7 kPa; – supply voltage of (24±4) VDC. The meters provide the possibility to select the measurement range input signal and to change the range indications and name of measurement unit. Meters Sch21.3, Sch22.4, Sch22.6, Sch23.3, Sch23.4, Sch23.6 provide the possibility to program thresholds for change in colour of indication of digital-analogue indicating device. Meters Sch20.3, Sch21.7, Sch23.7, Sch23.8 provide the possibility to set areas of colour warning of digital-analogue indicating device, which are formed with a number of single indicators of each colour preset in case of order. Buy