Proline Promag 50P, 53P
2
Hauser
Function and system design
Measuring principle
Faraday’s law of induction
states that a voltage is induced in a conductor moving in a magnetic field.
In electromagnetic measuring, the flowing medium corresponds to the moving conductor. The induced voltage
is proportional to the flow velocity and is detected by two measuring electrodes and transmitted to the ampli-
fier. Flow volume is computed on the basis of the pipe's diameter. The constant magnetic field is generated by
a switched direct current of alternating polarity.
A0003191
Ue = B · L · v
Q = A · v
Ue = induced voltage
B = magnetic induction (magnetic field)
L = electrode gap
v = flow velocity
Q = volume flow
A = pipe cross-section
I = current strength
Measuring system
The measuring system consists of a transmitter and a sensor.
Two versions are available:
• Compact version: transmitter and sensor form a single mechanical unit.
• Remote version: transmitter and sensor are installed separately.
Transmitter:
The Promag 50/53 transmitters incorporate a high impedance amplifier of 1 x 10
12
ohms or greater.
• Promag 50 (user interface with push buttons for operation, two-line display)
• Promag 53 (“Touch Control” without opening the housing, four-line display)
Sensor:
• 1/2" to 24" (DN 15 to 600)
Input
Measured variable
Flow rate (proportional to induced voltage)
Measuring range
Typically v = 0.033 to 33 ft/s (0.01 to 10 m/s) with the specified measuring accuracy
Operable flow range
Over 1000 : 1
Input signal
Status input (auxiliary input):
U = 3 to 30 V DC, R
i
= 5 k
Ω
,
galvanically isolated.
Configurable for: totalizer(s) reset, measured value suppression, error-message reset.
Status input (auxiliary input) with PROFIBUS DP and MODBUS RS485:
U = 3 to 30 V DC, R
i
= 3 k
Ω
, galvanically isolated
Ue
I
I
B
L
V
