Rosemount Analytical 400 / 400VP Endurance Conductivity Sensor
Starting at $524.00

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  • Process connection: 3/4 inch MNPT
  • Temperature: 32 to 221°F (0 to 105°C)
  • Temperature (option -60): 32 to 392°F (0 to 200°C)
  • Pressure: 250 psig (1825 kPa abs) maximum
  • Vacuum: 7.4 psia (51 kPa abs)
  • Cable length options:
    • 10ft cable standard
    • 50ft cable optional
  • Wetted materials:
    • Electrodes; titanium
    • Body; 316 stainless steel
    • Insulator; PEEK
    • O-rings; EPDM

The Rosemount Analytical Model 400 /400VP Endurance Conductivity Sensor are designed for direct screw-in insertion into process piping using a 3/4-inch MNPT fitting. The Model 400 sensors can also be used in sidestream samples. A 1-inch pipe tee with a 3/4-inch bushing is a suitable flow cell. A 3/4-inch pipe tee can be used with 0.1 and 1.0/cm cells. A transparent plastic flow cell is also available (PN 24091-02).

ENDURANCE sensors are contacting conductivity sensors. They are available in cell constants of 0.01, 0.1, 1.0, and 10/cm. The choice of cell constant depends on conductivity. High conductivity samples require larger cell constants. Consult the analyzer Product Data Sheet for recommended ranges and accuracy.

Sensors with 0.01, 0.1 and 1.0/cm cell constants have concentric titanium electrodes separated by a PEEK insulator. EPDM O-rings seal the internal parts of the sensor from the process liquid. Sensors with 10/cm cell constants have graphite electrodes and an epoxy body.

Electrolytic conductivity is a strong function of temperature, and conductivity readings are typically converted to the value at a reference temperature. To measure temperature, ENDURANCE sensors use a platinum RTD. In metal electrode sensors the RTD is inside the inner electrode. In the epoxy body sensor, the RTD is in a titanium thermowell protruding from the end of the sensor.

The Model 400 sensor is available with Variopol 6 quick disconnect watertight connectors. Wire the interconnecting cable to the analyzer and run the cable to the sensor. The sensor plugs into the cable receptacle. To replace the sensor, simply disconnect the Variopol fitting and plug in a new sensor. There is no need to rewire or rerun cable.


Rosemount Analytical 23747-00 Connecting Cable
Connecting cable terminated for Rosemount Analytical sensors
In Stock
Rosemount Analytical 9-conductor Extension Cable
Rosemount Analytical VP6 Cable
VP6 conductivity, amperometric cable for the Rosemount Analytical 400 series, available in 2.25 to 100ft lengths
In Stock


Please consider these optional accessories.

Rosemount Analytical 23550-00 Junction Box Remote
Rosemount Analytical 9210004 Conductivity Standard
Conductivity Standard, 2000 µS/cm, 16 oz
Rosemount Analytical 24091-02 Flow Cell
Low flow cell with polycarbonate, polyester, 316 stainless steel & silicon wetted parts
Rosemount Analytical 99CC Calibration Certificate
One certificate per lot at standard factory ranges only, includes the model, serial and/or tag numbers (does not include actual test data)
Rosemount Analytical Electronic Calibration
Certificate for specific unit, includes model, serial and/or tag numbers, test standards, NIST report numbers, & the actual test data
Rosemount Analytical Certificate of Origin
Original certificate of origin with chamber of commerce stamp

Application Notes

Here's how some of our customers used this product.

TDS in Rinse Loop

The Background: Our customer operates a chemical plating and etching facility. To control their production costs, they create their own demineralized rinse water via reverse osmosis. The customer seeks a way to measure the amount of total dissolved solids (TDS) in this rinse water to ensure it meets their standards for rinse water as well as to determine the overall health of their reverse osmosis system.

The Problem: TDS isn't a directly measurable parameter. Instead, electrical conductivity is measured and a correction factor is applied to the conductivity reading to obtain the TDS value. The correction factor varies and accounts for the minerals and salts that give the water its qualities.

The Solution: We recommended the Rosemount Analytical 400 series conductivity probe paired with the Rosemount Analytical Model 1056 analyzer. This combination creates a simple and effective system to prevent unclean water from entering the process. If the 1056 detects a TDS value above the customer defined threshold of 200ppm, the relay closes a vale and prevents the out-of-tolerance water from ever reaching the critical processes elsewhere in the facility.