Nuclear Density Meters vs Red Meters Industrial Measurement Systems

Next Gen measurment

Nuclear density meters have been used by industrial processes for years to determine the density of a slurry moving through a pipeline. Although they are recognized as “industry standard” operators have been under pressure to move away from nuclear density meters in recent years due to regulatory changes, increased operating and disposal costs and the desire to modernize their instrumentation.

Red Meters industrial measurement systems are used in place of nuclear density meters in mining, dredging, oil and gas and other similar applications. Red Meters isn’t the first non-nuclear density meter on the market. Is it another “too good to be true” solution that’s all claims and no proof? Let’s take a look.

Principle of Operation

Nuclear density meters function by measuring an emitted amount of radiation from the source, through the pipe and into the receiver. The difference between the radiation emitted from the source compared to the radiation accounted for at the receiver is then used to infer density. However, the path of the emitted radiation does not encompass the entire contents of the pipe, but rather a limited cross sectional line. By not measuring the entire contents, some portion of the media will continue to pass through the process without being measured.

Red Meters are more accurately described as an industrial measurement system rather than solely a density meter. They take multiple direct measurements of the process media and use those measurements to calculate density. Often used as an alternative to nuclear density meters in slurries, the inline measurement instrument’s technology is based around its patented flexible cartridge. The company’s flagship instrument, the Red Meter Toro, also has the capacity to integrate a flow meter onto a single unit which provides mass flow.

As material flows through the pipe, the cartridge bends slightly under the weight of the media. A high precision laser is used to detect the displacement in the deflection of the cartridge. Acting as a scale, the measurement of deflection is equated to a measurement of mass. In a fixed volume, the change in mass is divided by a stable volume. This is the most basic equation for density calculation. A variety of additional sensors measure pressure, temperature, wear and other variables. When combining these measurements, an operator can not only truly measure their process, but also accurately and efficiently make changes downstream and automate troubleshooting.

System Types

In the years since nuclear density meters were first created, major innovations have taken place in the sensor technology and computing realm. There are two types of technologies, legacy sensors and smart systems. Legacy sensor technologies measure one variable (i.e. density or temperature) and display readings locally and/or output to a control system. Any analysis of readings generated by a legacy sensor must happen externally.

Red Meters, which are smart systems, take readings from multiple sensors integrated within the system. Then, they calculate and display measurements such as density, temperature, pressure and the relationships between the variables. This allows the systems to measure and display more sophisticated measurements such as percent solids. Red Meters are also able to provide remote access and support, as well as system updates.

nuclear density meters vs
nuclear density meters vs


Any radioactive material is constantly decaying. This is gauged by the material’s half life, meaning the strength of emissions will halve over this time. In the industry this is called drift. This requires regular manual intervention for calibration in an attempt to maintain accuracy.
Nuclear density meters are measuring a section of pipe, meaning material not moving directly through the gamma rays can be missed. Environmental regulations necessitate ever smaller radioactive cores meaning weak and noisy emissions that need to be damped over long periods to be interpreted appropriately. These readings cannot be measured in real time. They also do not use a physical calculation for density, rather they are inferring density based on emittance and reception of gamma radiation.

Unlike density measurement methodologies which are using energy emission, be it nuclear waves, sound waves or ultrasonic waves, Red Meters systems work by measuring the deflection of the cartridge as the materials move through it. As such, Red Meters accuracy is highly dependent on the cartridge’s ability to return back to the baseline, ensuring there is no “drift” within the readings. Red Meters engineering team developed a proprietary cartridge which ensures repeatable readings. One key advantage of the Red Meter is that the entire volume of media inside the pipe is measured and displayed in real time.


Nuclear density meters start at an average of $10,000. The most important costs associated with a nuclear density meter is that they require monitoring, reporting, calibration and maintenance from a trained and certified Radiation Safety Officer. This is the most costly aspect of nuclear density meters. Removal or disposal of nuclear density meters has its own set of challenges. In some cases, disposal is more expensive than the acquisition cost of the meter.

Red Meters start at around $13,000. Pricing is determined by the diameter size of the unit which can be as large as 60” (1500mm.) There is limited upkeep and maintenance for Red Meters measurement systems, they are calibrated prior to shipping and only require installation onsite. The cartridge is a consumable part with built in wear sensors to alert when replacement is needed.

Ease of Use

Nuclear density meters require frequent, specialist human interaction to ensure they are operating correctly and within regulations. This includes “wipe” or leakage tests which must be performed to ensure no radioactive materials are leaking from the device. Nuclear density meters are used by specialist, certified staff who are familiar with their simple interfaces.

Red Meters systems were designed to be simple to install and use without any special training or certifications. Cinder, Red Meters latest industrial software, was built using the same softwar