FAQ for Level Transmitters

How should we select an appropriate level transmitter?

It is important to consider factors such as material conditions (solid, powder, slurry, liquid, etc.), material properties (corrosiveness, viscosity, dielectric constant, conductivity, etc.), and ambient conditions (temperature, pressure, humidity, etc.) when selecting an appropriate level transmitter.

For more details, please refer to the following article:

Are the adjustment apps available on each online store free of charge?

Yes.

You can download it free of charge.

Please feel free to download it.

What is the maximum distance for adjustment via Bluetooth communication?

The maximum communication range is up to 30 m under line-of-sight conditions.

Please note that the range may be reduced in the presence of obstacles such as buildings.

Under radio regulations, is the installation of microwave level transmitters in open space prohibited?

What differences allow millimeter-wave devices to be permitted?

Some microwave level transmitters comply with radio regulations as low-power radio devices. However, such compliant models have relatively low transmission power and are not suitable for powder measurement applications.

In contrast, millimeter-wave level transmitters are designed to comply with radio regulations as specified low-power radio equipment. They can be used outdoors and are suitable for both powder and liquid level measurement.

It is stated that materials with a low dielectric constant can be measured. What is the minimum dielectric constant that can be measured?

Although it varies depending on the material conditions, such as accumulation state and bulk density, a dielectric constant of around 2 can be used as a general reference.

We are currently conducting field tests with a variety of materials and have confirmed that materials with low dielectric constants—previously difficult to measure with conventional 26 GHz microwave level transmitters—can now be measured.

The test results will be published on our website once sufficient data has been accumulated.

Is an air supply required for air purging?

Air purging is designed to prevent material buildup on the emitting surface. If there is a risk of dust adhesion in your application environment, we recommend using it.

Is it possible to measure the liquid level in a narrow space within the beam angle?

Although it depends on the properties of the measured medium and the condition of the storage vessel, measurement is considered feasible as long as the reflection from the liquid surface can be detected.

We would welcome the opportunity to carry out an evaluation test.

What is the maximum measurement range for level measurement using a guide pipe (stilling well)?

The maximum measurement range confirmed in the actual field application is 5 m, while internal offline testing has demonstrated measurement capability up to 20 m.

There is foam on the liquid surface. Is it possible to measure the liquid level without being affected by the foam?

The influence of foam depends on its size and volume. As these characteristics vary depending on the properties of the measured medium, it is difficult to define a universal guideline.

However, based on our experience, relatively large bubbles (e.g., approximately 5 cm in diameter, similar to soap bubbles) allow signal penetration, enabling measurement of the actual liquid surface. In contrast, fine foam—such as that generated under rough sea conditions—tends to reflect the signal at the foam surface, preventing accurate measurement of the true liquid level.

In such cases, the use of a guide pipe (stilling well) has proven effective and may be considered as a solution.

If required, we can support on-site testing with a demo unit. Please do not hesitate to contact us.

Please note that modification of electrode dimensions is not supported.

Is there a method to measure without being affected by steam or condensation?

Yes.

26GHz radar level transmitter (microwave level transmitter) is recommended.

It can perform measurement by penetrating steam, even under conditions where the measurement surface is not visible due to heavy steam generation.

However, excessive condensation accumulating at the base inside the antenna may interfere with microwave signal transmission and reception. In such cases, the antenna interior should be purged with dry air or nitrogen (N₂) to remove the condensation.

For powder or slurry applications, dust carried by steam may adhere to and accumulate inside the antenna. In such situations, the use of an optional PTFE-coated antenna is recommended. This coating can utilize condensation to help clean the antenna surface.

Please note that this effect is only effective under continuous condensation conditions. If drying occurs during operation, the cleaning effect may be lost, and appropriate caution is required.

Are microwave level transmitters (26GHz radar level transmitters) compliant with the Japanese Radio Law?

We have two series of general 26GHz radar level transmitter and radar type river water level transmitter.

Radar Type River Water Level Transmitters are compliant with Japanese Radio Law.

They are designed in accordance with the provisions for low-power radio stations under the Radio Law.

However, compared to 26Ghz radar level transmitters, their transmission power is lower, making them unsuitable for applications involving powders or bulk solids with weak reflectivity.

Therefore, they are intended for liquid measurement only.

Could you please advise the power consumption of the 26GHz radar level transmitter?

The power consumption is 800mW.

There is foam on the liquid surface. Is it possible to measure the liquid level without being affected by the foam?

The influence of foam depends on its size and volume. As these characteristics vary depending on the properties of the measured medium, it is difficult to define a universal guideline.

However, based on our experience, relatively large bubbles (e.g., approximately 5 cm in diameter, similar to soap bubbles) allow signal penetration, enabling measurement of the actual liquid surface. In contrast, fine foam—such as that generated under rough sea conditions—tends to reflect the signal at the foam surface, preventing accurate measurement of the true liquid level.

In such cases, the use of a guide pipe (stilling well) has proven effective and may be considered as a solution.

If required, we can support on-site testing with a demo unit. Please do not hesitate to contact us.

Please note that modification of electrode dimensions is not supported.

Is it possible to operate the level transmitter using a solar panel when no power supply is available?

Yes.

We can provide a system configuration including a solar panel, battery, and wireless communication equipment.

What is the SN ratio?

The S/N ratio is the ratio between the signal strength (Signal), which represents the intensity of the reflected wave, and the noise signal (Noise).

Microwaves (radio waves) are invisible. Therefore, a PC software tool is used to visualize the waveform so that the measurement condition can be checked and adjusted.

In the displayed waveform, there are two components: the signal representing the strength of the reflected microwave and the noise generated during signal processing.

The S/N ratio is defined as the value obtained by subtracting the Noise level from the Signal level. It is an indicator of measurement stability.

As a guideline, stable measurement can generally be achieved when the S/N ratio is 10 dB or higher.

Can Matsushima Measure Tech's radar-type river water level transmitters communicate with standard HART communication modules?

Yes.

It is possible. However, as the driver for the HART communication module differs, the appropriate driver must be installed for proper communication.

Please advise the utility requirements for air purging of the radar-type river water level transmitters (e.g., air pressure, flow rate, etc.).

The required purge air pressure is 100 kPa, and the purge air flow rate should be 14 m³/h.

Is it possible to identify the faulty part when Sounding V outputs a fault alarm?

Yes.

The [MES] indicator flashes in case of wire-rope breakage.

The [POWER] indicator flashes in case of motor overload.

The standard measuring weight (Φ95 mm) of Sounding V is designed for materials with an apparent specific gravity of 0.4 g/cm³ or higher.

What happens if the apparent specific gravity is lower than 0.4 g/cm³?

An umbrella-shaped measuring weight (Φ280 mm) is available as an option.

It is suitable for materials with particle sizes of 1 mm or less.

For example, carbon black, lime powder, collected dust, etc.

What types of materials can be measured with Sounding V?

Sounding V can be used for powders, granules, and bulk solids.

The shape of the measuring weight may be changed depending on the properties of the material.

What is the minimum specific gravity measurable by Sounding V?

The minimum specific gravity is 0.1 or higher.

As a reference, materials such as wood processing dust have been successfully measured.

Why must a shielded cable be used between the Sounding M's main unit and the controller?

AC power is supplied from the controller’s internal circuit board to the Sounding M main unit.

Therefore, a shielded cable is required to prevent electrical noise.

A wire-break fault alarm was output from Sounding M's.

However, when we checked the site, the wire rope was not broken.

What could be the possible cause?

The contact of the auxiliary relay in the circuit that lowers the measuring weight may have become oxidized due to sparking, causing poor electrical contact.

What is the recommended measurement interval for Sounding M's?

A measurement interval of 30 minutes or longer is recommended.

If the measurement frequency is too high (i.e., the interval is too short), components such as the motor and wire rope may deteriorate more quickly.

We also recommend planning periodic replacement of consumable parts.

Can Matsushima Measure Tech's signal conditioners communicate with standard HART communication modules?

Basically, it is possible.

However, since not all equipment has been evaluated, we recommend conducting a preliminary evaluation using a loan unit if there are any concerns.