Application
Designed for remote level measurement of liquid, viscous and bulk media (including explosion hazardous).

Is used in contemporary automation systems on objects of oil and gas, chemical, pharmaceutical, food and municipal industries.

Main operation sites: Oil and gas stations, tank farms, refineries, starages and other automated systems in oil and gas, chemical, pharmaceutical, food and municipal industries.

Features
non-contact measurement
light-weight and space-saving design
housing dismantling (if required) without tank depressurization
applicable for tanks with various nominal diameter and height of mounting flanged pipe (for design with waveguide extender)
simple application, commissioning and maintenance
controlled medium temperature is only limited by temperature of mounting flange surface inside tank, from minus 50 to plus 100 °C
protection against noise caused by tank design
shock-resistant housing made of aluminum alloy or corrosion-proof steel
explosion-proof modification
transit connection
continuous self-testing
various types of mounting devices for protective cable sheath (metal hose conduit, armored cable, pipe)

Design, principle of operation
The metal rod with reed switches (in correspondence with measured levels quantity) is placed inside the guide pipe. Board are connected serially with two wires, forming a variable resistor with resistance determined by the liquid level. When liquid level is minimal (all floats lay down the stoppers), the resistor circuit provide maximal resistance. When the liquid level rises, the floats alternatively rise and close the terminals of reed switches that shunt the resistors, thus, the total circuit resistance is decreased. The signal is converted to a digital signal by controller and then transmitted via RS-485 interface Modbus protocol. Control levels value adjustment, is executed by moving of reed switched and their stoppers along the rod. The quantity of control levels might also be altered.
The terminal clamps «2» on PMP-165 board are designed for connection of the board with reed switches, terminal clamps «3» are used for connection of sensor to power line, terminal clamps «4» are used for connection of level sensor via RS-485 interface.

Switch 5 is designed for reset to default settings. The following parameters shall be reset: Modbus address, data transfer speed, pairity mode. Switch 6 locks the possibility of these parameters altering. Terminals «1» are used as additional contacts (see. OM).

Specifications
Operational measurement range, m from 0.8 to 20
Acceptable main inaccuracy of level measurement, mm ±4
Level measurement discreteness, mm: 0.5
Number of measurements per second, at least 1
Time of operation mode setting, min, not more than 2
Monitored media features: temperature of mounting flange inside the tank, °C from -50 to +100
pressure, MPa, not more than 2.5
relative dielectric permittivity, Ɛ, at least 1.8
Temperature for operation, storage and transportation, °С from -40 to +70
Water and dust ingress protection degree (IEC 60529) IP66
Explosion protection marking Ga/Gb Ex d IIB T4 X; no explosion protection – general industry modification
Length of power and signal line, m, not more than length of signal line 1500 (SENS); 1200 (RS-485)
Power supply voltage (acceptable), V from 8 to 36 (DC)
Power consumption, W, not more than 2.5
Mean time between failures, hours, not less 100 000
Minimal weight, kg min 6 (depends on modification)
Service life, years 15