A density gauge measures how dense the material moving through a process is, without anyone having to divert or collect a sample for every reading. In mining and mineral processing, that measurement helps operators monitor process conditions, support control decisions and pick up changes in the material being handled.
This guide explains what a density gauge does, how the measurement works in general terms, what can move the reading, and what a service visit involves.
- A density gauge measures the density of material in a running process, rather than requiring a laboratory or static test for every reading.
- Density describes how much mass sits in a given volume of material.
- Many industrial density gauges use a source and detector arrangement, and some of those sources are sealed radioactive sources.
- Process changes, build-up, flow conditions, electronics faults and configuration can all move the reading.
- Accurate Industries can assist with density gauge inspection, fault finding, calibration support, repairs and ongoing maintenance.
What is a density gauge?
A density gauge is an industrial measuring instrument that determines the density of material flowing through a process. It mounts around, beside or in a suitable measurement section, and the exact arrangement depends on the equipment, the material, the pipework or vessel, and what the site needs to measure.
How does a density gauge work?
Many industrial density gauges use a source and a detector. The source directs a measurement signal through or towards the process material, and the detector measures what arrives on the other side, or at the selected measurement point.
As the density of the material changes, the measured signal changes with it. The gauge electronics interpret that change and produce a density value or a related process output. This lets the plant monitor density while it operates, so the material does not have to be diverted, stopped or collected for every measurement.
The measurement principle, installation arrangement, electronics and calibration method vary between systems. Any setup has to be considered alongside the process, the material characteristics and the site requirements.
Where are density gauges used?
Density gauges suit a range of industrial applications, particularly in mining and mineral processing. Typical locations include process streams, slurries, pipelines, vessels and other points where continuous density information is useful.
Whether a density gauge suits a given duty depends on the process conditions and the equipment design, so a site assessment usually comes before selecting, installing or modifying a system.
What can affect a density gauge reading?
Both the process and the condition of the equipment can move the reading. Contributing factors include:
- changes in material composition;
- changes in solids concentration;
- air, voids or inconsistent flow;
- material build-up around the measurement area;
- changes in pipe, vessel or process geometry;
- detector or electronics faults;
- cable, power or communications problems;
- incorrect configuration or calibration; and
- mechanical movement or damage.
An unusual reading does not identify its own cause. In most cases it needs a process check, an equipment inspection and a review of the measurement system by a qualified technician. Our guide on density gauge troubleshooting sets out where to start.
Does a density gauge use radiation?
Some industrial density gauges use a sealed radioactive source and a detector as part of the measurement system. That is not the same as the process material becoming radioactive. The equipment, the source and the installation must be managed according to the applicable site procedures and legal requirements.
Only appropriately trained and authorised personnel should carry out radiation work. Do not remove, open, bypass or interfere with a source or its shielding. If you have any concern about the equipment, contact Accurate Industries or your site radiation safety personnel.
What does a density gauge service visit involve?
The work depends on the equipment and the site, but a visit may include:
- planning with the site before attendance;
- completing site inductions and the required safety processes;
- inspecting the gauge, the mounting arrangement and the surrounding equipment;
- checking the process measurement conditions;
- reviewing cables, connections, signals and electronics;
- cleaning accessible areas where build-up affects the measurement;
- checking the measurement response and calibration condition;
- recording findings, readings, photographs and recommendations;
- repairing or replacing components where authorised; and
- providing service records and maintenance recommendations.
We can retain service records and reporting against the relevant asset in AIMM, the Accurate Industries Maintenance Manager, where this is included in the service arrangement.
Can Accurate Industries service my density gauge?
Yes. We service density gauge equipment across mining and other industrial applications, including inspection, fault finding, calibration support, repairs, replacement components and ongoing maintenance. The exact work depends on the model, the installation, the process and the site requirements, so contact the team with the equipment details and the problem you are seeing.
Density gauge safety and compliance
This guide provides general information about density measurement. It is not a radiation safety procedure, a source handling instruction or a substitute for your site requirements.
Installation, inspection, testing, calibration and repair have to be carried out in accordance with the equipment documentation, site procedures and the applicable Australian requirements, by appropriately qualified and authorised personnel.
Frequently asked questions
Is a density gauge the same as a belt weigher?
No. A belt weigher measures material moving on a conveyor by combining belt load and belt speed, as our guide on how a belt weigher works explains. A density gauge measures the density of material at a selected process location. A site may run both, but they perform different measurement functions.
Can a density gauge measure continuously?
Many industrial density gauge systems provide ongoing process measurement while the plant operates. The available output and measurement behaviour depend on the equipment and the installation.
What should I do if the density reading looks wrong?
First check whether the process or the material has changed. If the reading still looks abnormal, arrange an inspection, since build-up, wiring, electronics, configuration, calibration and process conditions can all contribute.
Can I work on the radiation source myself?
No. Do not open, remove, bypass or interfere with a radiation source or its shielding. Contact Accurate Industries and your site authorised radiation safety personnel for assistance.
Does Accurate Industries work on older density gauges?
We can assess selected older and third party equipment. Support depends on the equipment condition, the available information, parts and the site requirements.
Need help with a density gauge?
We can assist with density gauge assessment, service, calibration support, repairs and ongoing maintenance and spares. Contact the team with the gauge details, the process application and the symptoms being reported.