User's Manual
Table Of Contents
- Table of contents
- Important document information
- Terms and abbreviations
- Registered trademarks
- Product life cycle
- Measuring principle
- Input
- Output
- Electrical connection
- Performance characteristics
- Installation
- Environment
- Process
- Mechanical construction
- Operability
- Certificates and approvals
- Ordering information
- Accessories
- Supplementary documentation
Micropilot FMR20
8 V. 5, Rev. 3, 20-12-2016 Endress+Hauser
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 Maximum measuring range
FMR20 with 40 mm (1.5 in) antenna 10 m (33 ft)
FMR20 with80 mm (3 in) antenna 20 m (66 ft)
Requirements of the installation
• recommended tank height > 1.5 m (5 ft) or media with low DC 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.
The following table describes the media groups.
Media groups
ε
r
Example
4 to 10 E.g. concentrated acid, organic solvents, ester, aniline, alcohol, acetone.
> 10 Conductive liquids, aqueous solutions, diluted acids and bases
Reduction of the max. 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
Distance Mean power density in the direction of the beam
1 m (3.3 ft) < 12 nW/cm
2
5 m (16 ft) < 0.4 nW/cm
2