Radiometric Moisture Measurement LB 350

Moisture measurement no application-related restriction

The moisture measurement system LB 350 is primarily used for applications, which can’t be solved with conventional sensor technologies due to conductivity or particular chemical properties of the material to be measured.

Benefit from the large measuring volume of 1m diameter, leading to absolutely representative measurement results. The measurement is carried out either from the outside, through the bunker walls or by using a robust dip pipe which is installed inside the bunker. The measuring instrument itself is therefore not subjected to wear and tear.

The LB 350 has proven to work highly precise and reliable in numerous difficult applications like the moisture measurement of coke, sinter, sand, gravel or lime-sand brick.  

Measuring Principle

The measuring system LB 350 utilizes the neutron measurement technology.
Learn more about our neutron moisture measurement


System Configuration

Depending on the application and requirements, either the surface probe or the bunker probe can be used.

Surface Probe

The surface probe is mounted directly on the outer wall of a bunker. It is cabable to irradiate up to 20 mm thick steel walls. However, the best measuring accuracy is achieved by using our specifically designed mounting frame, which is installed in an opening in the wall. The mounting frame is extremely robust due to the wear-resistant ceramics surface and allows for a quick and easy installation of the probe.


Bunker Probe

The probe is mounted in a dip pipe made from steel or ceramics. Typically this dip pipe is inserted in the outlet section of the bunker, so that the probe is fully surrounded by bulk material. Due to the optimum position of the probe inside the material flow, a highly representative measurement is achieved.



 Technical Data LB 350

Evaluation unit
LB 350



LB 350-1: aluminum wall housg. IP 54
weight approx. 4.3 kg

LB 350-2: 19” rack 3HE
weight approx. 4.8 kg

LB 350-3: 19” rack 3HE
accommodating 2 channels for moisture density compensation
weight approx. 6.3 kg


AC voltage:
+10% to -15%, 47-65Hz

DC voltage:
24VDC (18 - 36VDC)

Power consumption

max. 25 VA

Operating temp

0 ... +50°C (32 ... 122 °F)

Storage temperature

-40 ... + 70°C (-40 ... 158 °F)

Analog output

Moisture signal 0/4 - 20mA,

isolated, load: max. 500 Ohm

Detector connection

7 - wire
Supply (+/- 15V DC) and pulse line on
separate wires

Digital input

"Hold" signal
by external contact closing

Digital output

3 relay contacts for:

- collective fault message
- limit value max
- limit value min

Max. 250VAC / 2A non-inductive

Attainable Accuracy

± 0.1% depending on application


se t up via code numbers


by means of 6 push buttons


max. 5 digits


Right to implement technical improvements and/or changes without prior notice reserved.


Format Size
LB 350 Moisture Measurement on bulk materials en PDF 287.15 KB
Whitepaper Radiometric Measurements Accurarcy, repeatability and errors en PDF 739.65 KB
Format Size
ATEX LB 35.. en PDF 877.23 KB
Operation Manual
Format Size
LB 350 en PDF 5.9 MB
Product Information
Format Size
Moisture measurement with bulk density compensation en PDF 1.58 MB
On-line Coke moisture meter en PDF 839.37 KB
Project Questionnaire
Format Size
Neutron Moisture en PDF 6.96 KB
Neutron Moisture Questionnaire en PDF 74.68 KB
Technical Information
Format Size
LB 350 de, en PDF 2.66 MB