KROHNE UFM 3030 EEx EN - Manual (Page 7)

UFM 3030 7
1.3 Flow sensor
1.3.1 Standard
instruments
The UFS 3000…-EEx flow sensor is the default measuring unit of the UFM 3030 (3-beam)
ultrasonic flowmeters. It contains the ultrasonic sensor (three pairs of opposite transducers) in type
of protection intrinsic safety category "ib" according to EN 50020. All sensor circuits are wired by
separate coaxial cables and connected through SMB connectors, which are marked by the
respective numbers 1.1, 1.2, 2.1, 2.2, 3.1 and 3.2. The flow sensors are available in size DN25 (1”)
up to DN3000 (120”) in diameter.
The UFS 3000…-EEx flow sensor is used in combination with the flow converter unit type UFC
030…-EEx, which is either directly mounted on top of the flow sensor (compact meter) or installed
on a distance and connected via a cable (separate version). In the last case the flow sensor as well
as the flow converter unit are both provided with a junction box, in which the SMB connectors are
mounted.
The UFS 3000 F/…-EEx flow sensor in separate design is the measuring unit of the separate
flowmeter system. There is a standard version, suitable for process liquid temperatures from -25°C
up to 180°C and an extended temperature (XT) version UFS 3000 F/XT-EEx, which allows a
maximum process temperature of 220°C. Both versions are designed for an ambient temperature
in the range of -40°C up to +65°C.
The UFS 3000 F/…-EEx flow sensors in separate design are classified according to the
temperature classification table below.
Maximum process liquid temperature at Ta = 65°C Temperature class
Standard design XT-design
T6 80°C 80°C
T5 95°C 95°C
T4 130°C 130°C
T3 180°C 195°C
T2 N.A. 220°C
The UFS 3000 F/…-EEx flow sensors are marked with the explosion safety codes:
•
Standard UFS 3000 F-EEx: II 2G EEx ib IIC T6…T3
•
XT-version UFS 3000 F/XT-EEx: II 2G EEx ib IIC T6…T2
The intrinsically safe "ib" ultrasonic sensor circuits inside the UFS 3000…-EEx flow sensor have
the following maximum values (i.e. entity parameters):
•
Maximum input voltage : Vmax = 13.1 V
•
Maximum input current : Imax = 600 mA
•
Maximum internal capacitance : Ci = 13.1 nF (maximum, 3 sensor circuits)
•
Maximum internal inductance : Li = 134 µH (maximum, 3 sensor circuits)
The intrinsical safe sensor circuits of the UFM 3030 K/…-EEx compact flowmeter
are only internal circuits and not accessible for the user.