Installation Instructions

Micropilot FMR20 Modbus RS485
Endress+Hauser 7
Input
Measured variable
The measured variable is the distance between the reference point and the product surface.
The level is calculated based on E, the empty distance entered.
Measuring range Maximum measuring range
• Device with 40 mm (1.5 in) antenna: 10 m (33 ft)
• Device with 80 mm (3 in) antenna: 20 m (66 ft)
Installation requirements
• Recommended tank height > 1.5 m (5 ft) for media with low ε
r
value
• Open channel minimum width 0.5 m (1.6 ft)
• Calm surfaces
• No agitators
• No buildup
• Relative dielectric constant ε
r
> 4
Usable measuring range
The usable measuring range depends on the antenna size, the medium's reflective properties, the
installation position and any possible interference reflections.
Media groups
• ε
r
= 4 to 10
e.g. concentrated acid, organic solvents, ester, aniline, alcohol, acetone.
• ε
r
> 10
e.g. conductive liquids, aqueous solutions, diluted acids and bases
Reduction of the maximum possible measuring range by:
• Media with bad reflective properties (= low ε
r
value)
• Formation of buildup, particularly of moist products
• Strong condensation
• Foam generation
• Freezing of sensor
Operating frequency
K-band (~ 26 GHz)
Transmission power
Mean power density in the direction of the beam
• At a distance of 1 m (3.3 ft): < 12 nW/cm
2
• At a distance of 5 m (16 ft): < 0.4 nW/cm
2
Output
Digital output Modbus®
Dedicated differential Modbus interface via separate wire pair
Bluetooth® wireless technology
The device has a Bluetooth® wireless technology interface and can be operated and configured via
this interface using the SmartBlue app.
• The range under reference conditions is 25 m (82 ft)
• Incorrect operation by unauthorized persons is prevented by means of encrypted communication
and password encryption
• The Bluetooth® wireless technology interface can be deactivated