Rheonics Support

What is the purpose of this article?
Explore the possible methods for protecting the M12 connector and cable of Rheonics sensors to achieve the desired protection rating in the field.

What products are involved?
Rheonics sensor cables, probe connectors, and accessories for connection protection in the field

TABLE OF CONTENTS

M12 connector in Rheonics' viscometers and density meters

Protecting the M12 connector cable from the elements in a field installation

Selecting the correct cable variant to achieve the right IP rating on the sensor probe

Accessories and alternatives for cable protection

1. Impact shield for sensor cable protection

2. Protecting the sensor cable from near-ambient process conditions

3. Rheonics' SR-TT alternative for cable protection

4. Protection for submersion

M12 connector in Rheonics' viscometers and density meters

Rheonics' sensor probes come equipped with a male M12 connector at the back of the probe. This connection powers the probe and sends data to the electronics module. Here is where the sensor cable connects using either a straight or 90-degree female M12 connector.

Figure 1: Rheonics SRD X3 showing the M12 connector at the back of the sensor probe

Protecting the M12 connector cable from the elements in a field installation

When installing instruments in the field, these are often left exposed to fluctuations in temperature and ambient conditions. For this reason, these must be made of durable materials, capable of withstanding the effect of the elements. Often connectors or cables are the weak points for outdoor or field installations. In the case of Rheonics' sensor probes, these are rated as IP69K only and are limited by the protection rating of the connection between the sensor cable and the probe’s M12 connection, bringing the whole sensor assembly’s IP rating down. Here, we will explore the alternatives Rheonics offers in terms of connectors and cables, and explain how this can translate into an installation with a high IP rating, especially relevant for hazardous or aggressive environments.

Figure 2: Cable/connector variants offered by Rheonics (left to right): Standard straight, Standard 90°, Patch HT, IP69K, EX.

Selecting the correct cable variant to achieve the right IP rating on the sensor probe

The correct selection of the sensor cable is the first step to achieving the desired protection rating in the installation of Rheonics sensors in the field.

Rheonics offers the sensor cable variants shown in the table below. For a detailed article on these, click here. These variants cover most of the use cases, however, customers may also supply their cable if special specifications are required.

Table 1: Cable variants for Rheonics SR-Type sensors

Accessories and alternatives for cable protection

1. Impact shield for sensor cable protection

Connectors and cables may also be susceptible to wear and tear due to tension or flexion. They can also become prone to impacts from moving machinery, equipment, or tools. For this, Rheonics offers the IMS-SR - Impact Shield for SR-Sensors compatible with straight and angled cables. This shield attaches to the body of the probe and provides mechanical protection from collisions or excessive bending of the cable at the connection point.

Figure 3: Impact shield IMS-SR installed on an SRV-X1-34N

2. Protecting the sensor cable from near-ambient process conditions

Additionally, sometimes the sensor’s connector may need to be positioned within process conditions. Here, the cable and connector are required to support the process conditions (temperature, pressure, humidity, etc.) For this, Rheonics offers the X1 (with the TMA adapter) and the X8 variant. While these are not suited for processes with high temperatures or pressures they are alternatives when operating near ambient conditions. For more information on these variants, visit their respective article:

TMA-34N - Installing density & viscosity sensor in Tank - with Rheonics tank mount adapter  

SRV-X8: Teletube Ultra-long Insertion Viscometer 

SRD-X8: Teletube Ultra-long Insertion Density and Viscosity Meter  

Figure 4: SRV X8 connected to the SME-TRD (left) and SRD X8 using a cable gland (right) the same is possible for the X1 with TMA 34N accessory.

3. Rheonics' SR-TT alternative for cable protection

In addition, Rheonics also offers the SR-TT probe that comes with a G3/4” threaded back side. This can be further adapted to an NPT 1/2” with the AT-TT accessory, allowing two threaded alternatives for the customer to connect rigid tubing or flexible cable sleeves/hoses from the cable connector to the electronics cabinet. A more in-depth article regarding cable protection specifically can be found here.

Table 2:Drawings for SR-TT threaded alternatives

4. Protection for submersion

Special applications may require the whole probe, and therefore the connector to be submerged in fluid. This usually happens when using the X1 with TMA, the X8, or the SR-TT. In these applications, there exists already a physical barrier protecting the cable from the process fluid (i.e. the metal pipe that houses the cable), nonetheless, it is always important to add a second layer of protection from the high levels of humidity and temperature near the application.

In these cases, two approaches can be taken. 

1. Use IP69K cable:

2. Use a protection sleeve (called seal boot) over it:

References

[1]. Shield and Strain Relief Kit - Straight Cable Clamp