Rosemount 396R and 396RVP TUpH pH ORP Sensors

Rosemount 396R and 396RVP pH/oxidation reduction potential (ORP) sensors are available in 21 in (533 mm) and 36 in (914 mm) titanium tube sensor lengths for use with a ball valve (sold separately) for hot tap applications. Rosemount 396RVP sensors feature a Variopol cable connection for use with VP8 quick disconnect interconnecting cables (sold separately).

Let's break down what the Rosemount 396R and 396RVP assemblies are and how they work with TUpH pH and ORP Sensors.

Core Concept: Assembly + Sensor

This describes two parts that form a complete measurement installation:

1. The Mounting Assembly: Rosemount 396R / 396RVP (The hardware that holds the sensor and connects it to the pipe/tank).

2. The Sensing Element: Rosemount TUpH (The actual intelligent pH or ORP electrode that performs the measurement).

Part 1: The Mounting Assemblies (396R vs. 396RVP)

These are retractable assemblies that allow you to remove the sensor for maintenance or calibration without having to shut down the process or drain the line/tank. This is a critical feature for safety and operational efficiency.

Rosemount 396R

• R = Retractable

• This is a retractable assembly without a valve.

• How it works: The sensor is mounted at an angle (typically 45° or 90°). To remove it, you must first shut down the process, depressurize the line, and drain the section where the sensor is installed. Only then can you unscrew and retract the sensor.

• Use Case: A lower-cost option for applications where process shutdown for sensor maintenance is acceptable.

Rosemount 396RVP

• R = Retractable

• V = Ball Valve

• P = Flow Chamber (a small chamber that directs process flow across the sensor tip)

• This is a retractable assembly with an integral ball valve.

• How it works: The ball valve allows you to isolate the sensor from the process pressure. You can close the valve and then retract the sensor for maintenance or calibration while the process is still running. This is the primary advantage and the reason for its widespread use.

• Use Case: The standard choice for most applications where continuous process operation is important. Essential for hazardous, hot, or high-pressure media.

Visual Difference: The 396RVP will have a noticeable valve handle on the assembly, while the 396R will not.

Part 2: The Sensing Elements (TUpH pH / ORP Sensors)

The TUpH series are the smart, programmable sensors that thread into the assemblies above.

• TUpH: Stands for "Transmitter compatible, Universal pH."

• pH Sensors: Measure the acidity or alkalinity of a solution (pH scale of 0-14).

• ORP Sensors: Measure the Oxidation-Reduction Potential (in millivolts, mV), indicating the solution's ability to oxidize or reduce contaminants. Common in disinfection (chlorine, ozone) and wastewater treatment.

Key Features of TUpH Sensors:

• Smart Preload: The sensor stores its calibration data, so if you replace it, the new sensor can automatically upload its calibration, minimizing downtime.

• Dual Preload: Stores calibration data for two different buffers.

• Various Form Factors: Available in different lengths and materials (e.g., PPS, PVDF) to suit various chemical compatibilities and insertion depths.