Which products are involved?

Inline process viscometer SRV  and inline process density meter SRD

Visit Rheonics product page: Products » inline fluid viscometer and density meter

1. What is the importance of a clean probe?

Accurate measurements of process fluid density and viscosity are an important part of many industrial processes, and cleanliness plays a major role in obtaining accurate readings. Often the process fluid causes deposits and measurement probes should be cleaned to ensure accurate viscosity and density measurements.

Dirt, debris, sticking material, and other contaminants can interfere with the sensor operation and cause incorrect readings. The SR probes are a stable, robust sensor system that operates over a wide range of temperatures and pressures. The standard sensor is made of 316L stainless steel, which is one of the most widely used materials in manufacturing processes involving fluids. 

The SRV and SRD sensors are based on a resonant sensing element that operates in the range of approximately 7-8 kHz. The sensor measures fluid properties in a layer of fluid surrounding the resonant element. The sensor measures what it is in contact with so it is important to ensure that fluid that is of interest is in contact with the sensing element at all times.

If the sensor sensing element gets coated with sticky fluid and solids, it is recommended that the sensor is cleaned. This cleaning often takes place in situ aka the sensor is cleaned along with the line or vessel it is installed in. However, at times it is desired or important to remove and mechanically clean the probe/sensing element.

Adherent films can be removed by using appropriate solvents and/or wiping with a cloth or paper. Under no circumstances should abrasives be used to clean the resonator, as these will change the geometry and destroy its calibration. 

Do not use ultrasonic cleaners under any circumstance as that could damage the probe internal components.

2. Removing the coating with a solvent-saturated cloth or paper

Cleaning SR (SRV or SRD) probes requires a gentle hand and the right materials. To start, use a soft cloth to wipe down the SR probe thoroughly. Make sure to remove any grease or dirt buildup that may have accumulated on its surface. Then, dampen a clean cloth with warm water and mild dish soap. Gently wipe down the stainless steel probe with the cloth and rinse it off with clean water. Finally, dry the stainless steel probe with a soft cloth. With these steps, your SR probe will remain clean and perform its best.

When it comes to stainless steel probes, it's important to keep them clean in order to protect the material from corrosive elements. Washing stainless steel probes with warm water and mild detergent can help prevent corrosion. For tougher soils or stains, a stainless steel cleaner or vinegar-based solution can be used on the probes. It is important to remember not to use any harsh abrasives, metallic scouring pads, or steel wool as these can damage stainless steel surfaces. 

3. Chemical compatibility for Stainless steel 316

When it comes to chemically cleaning the Rheonics sensors, there are many different chemical solutions available. The most popular solution is a mixture of water and detergent, which can help remove dirt, dust, and other foreign materials from the stainless steel surface. It is important to note that stainless steel should not be exposed to harsh chemical cleaners for long periods of time, as this can cause damage to the surface. Additionally, stainless steel should always be dried thoroughly after being chemically cleaned in order to avoid any corrosion. 

The following table can be used to verify the compatibility with different chemicals:

A: Asphyxiant(Gas and vapor only)

C: Corrosive

F: Flammable

O: Oxidizer

T: Toxic

4. Commonly used cleaners

4.1. Alkaline cleaning

4.2. Caustic (Sodium Hydroxide)

4.3. Acidic cleaning

5. CIP/SIP compatibility