Low ppb Optical Dissolved Oxygen Sensor, Hamilton VisiTrace

The VisiTrace DO is designed to measure dissolved oxygen in the low ppb range in brewing applications, notably during filtration and filling. Adjacent markets are also boiler feed water in power plant . The VisiTrace DO offers all the advantages of Hamilton`s optical dissolved oxygen sensors: fast response time and easy maintenance. Improvements compared to conventional electrochemical (amperometric) sensors include flow independence, rapid start-up with no polarization time and implified maintenance. Monitoring in low ppb ranges is essential in many applications such as brewing processes and power plants.

VisiTrace DO provides the ability to rapidly and precisely perform measurements across its 0 - 2,000 ppb dissolved oxygen range. It provides accurate and undistorted results across all conditions and concentrations and is not affected by flow, pressure or presence of CO2. Startup is quick because the optical sensor does not require polarization. Maintenance is easy and seldom required – just a quick exchange of the sensor cap.

The VisiTrace utilizes luminescent technology and eliminates the typical drawbacks of membrane components. The measurement is unaffected by sample fouling or poisoning and virtually maintenance free with no membranes to replace, no electrolyte solution to replenish, no anode or cathode to clean or replace and long calibration intervals.


  • suitable for steam sterilization, autoclavation and CIP
  • flow independant; self diagnostics
  • electrolyte-free so no leakages occur
  • no membrane so no concerns about air bubbles
  • no polarization time required
  • easily replacable sensor cap containing the sensing element
  • replacement sensor caps available
  • measurement not affected by sample color or turbidity
  • connector heads: VP 6 or Arc (VP 8)



For power plants, maintaining low oxygen levels in the boiler water is a critical control parameter. Oxygen is the primary source of boiler corrosion. Controlling the dissolved oxygen content to low ppb ranges is important to reduce downtime resulting from corrosion. Unlike amperometric DO sensors, the optical Visitrace DO is not affected by hydrogen that is sometimes generated when hydrazine is used as an oxygen scavenger.

For breweries a key advantage of the Visitrace DO is the optical sensor cap that is resistant to cleaning solutions containing chemicals such as active chlorine and chlorine dioxide. Also, the robust sensor does not need calibration after each CIP cycle. This assures reliable operation with minimum maintenance. A microtransmitter integrated in the sensor head delivers a 4-20 mA output measurement directly to the process control system without need of a separate transmitter.  Setup, calibration, diagnostic and other relevant data is saved in its on-board memory. Integrated Bluetooth 4.0 makes it possible to wirelessly monitor, configure and calibrate the VisiTrace sensor from smartphones and tablets.  

The VisiTrace sensor is coated with a luminescent material. Blue light from an LED is transmitted to the sensor surface. The blue light excites the luminescent material. As the material relaxes and falls back into its ground state, it emits red light.

The time from when the blue light was sent and the red light is emitted is measured. The more oxygen that is present the shorter the time it takes for the red light to be emitted. The time delay can be expressed as a phase shift between the wave patterns of the Blue LED light and the Fluoresced light. This phase shift is inversely proportional to the oxygen concentration in the fluid.

The ODO Cap L0 is intended for the measurement in the low ppb range in breweries and soft drink processing. The optical oxygen sensors are the first sensors with integrated opto-electronics, having the full functionality of a measuring device with selfdiagnostics. It is steam sterilizable, autoclavable and CIP compatible. The optical sensors requires less maintenance than a classical oxygen sensor as it does not have a mechanically sensitive membrane or a corrosive electrolyte. Available only for VisiTrace DO sensors.

Standard Replacement Cap- Part Number 243530


Hot-Tap Retractable Assembly, Model PR10

On-line measurements often present extra challenges, especially when routine maintenance is required. The PR10 is ideally suitable for applications where the sensors must be removed without interrupting or shutting down the process. Without any special tools the PR10 can be retracted safely from the process at pressures up to 5 bar (72 psi). The PR10 is a universal retractable assembly that can be used for all liquid measurements. The PR10 is designed to accept any commercially available pH/ORP or dissolved oxygen sensor that has a PG13.5 connection while still being backwards compatible with old Yokogawa electrodes.

For ease of use optional flush ports are available. In the retracted position the sensor can be kept moist, cleaned or even calibrated. This can all be done without process interruption or disassembly of the armature.

YouTube Main IconTraining Video: 
videoIcon1PR10 Installation and Extraction


  •  One model for pH/ORP, dissolved oxygen, conductivity and inductive conductivity sensors
  • All commercially available pH electrodes, such as PG13.5, SMART sensors, Vario Pin, YEF and DIN connectors can be installed in the PR10.
  • Integrated protection cage
  • A "scraper" is built-in to each assembly to effectively scrape or wipe off the
    process from the PR10's shaft as it is being retracted from the process.
  • A safe "through the valve" insertion and retraction design
  • Simplified installation by optional ball valves with flanged or tapered connections
  • Optional flush port accessories makes it easy to keep sensors moist (pH) and clean, and also provides access for calibration if desired. 

PB30 Floating Ball- S200256U1

The PB30 floating ball holder features a design which minimizes fouling by the process. A brass ring around the sensor facilitates a check for membrane integrity, and helps to eliminate any deposits of algae, making a cleaning system unnecessary for the model PB30. Maintenance is very simple, with only periodic inspection and calibration needed. 

Mini Flow Through Holder, Model K1598AC

When you use the adapter fitting, part number M1263LP, it converts any PG13.5 connection to a 3/4" MNPT. This allows for installation into the mini flow thru holder with a 1/4" NPT inlet and outlet. 

Other adapters are available for easy installaltion into the F*20 pH/ORP series of holders and the F*40 conductivity series of holders. 


Looking for more information on our people, technology and solutions?

Contact Us