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What is Rhodamine?

Rhodamine is a fluorescent tracer dye that mimics the movement of water molecules and indicates how water moves. Monitoring rhodamine in water is useful for tracing pollutants, studying aeration and dispersion, and many other applications when it is necessary to understand the movement of water.


One of the most common uses of rhodamine is measuring time of travel for surface, ground and waste water. Time of travel refers to the movement of waterborne substances, from one point to another in a stream during steady or gradually varied flow conditions. This form of rhodamine testing involves rhodamine being injected into the water, with the concentration of the dye is measured at other locations downstream using a fluorometer.

The fluorescent properties of rhodamine mean that when it is irradiated with a light of a particular wavelength it emits a light of a higher wavelength. The rhodamine sensor measures the light fluoresced by the rhodamine. The concentration of the dye in the water is relative to the fluorescence, so this measurement gives an accurate indication of the rhodamine levels in the water sample.

Aquaread’s multiparameter water testing equipment

Aquaread are award winning manufacturers of rugged yet precise multiparameter water testing equipment. The Aquaprobe devices are constructed from tough materials that are ideal for use in the field.


The majority of the probes measure a set range of standard parameters, such as temperature, pH and electrical conductivity. They have additional sockets to take optional ion specific electrodes, and optical electrodes so that the user can tailor the device to meet their requirements. If you wish to carry out continuous flow monitoring, the Aquaprobe AP-7000 would be ideal because it is designed especially for long term, unmanned deployment. The Aquaprobe AP-5000 and Aquaprobe AP-2000 are also suitable for fixed monitoring over short to medium time periods.


Why use an Aquaread rhodamine meter?

Water rhodamine meters are the ideal solution because they can be left unattended for days or weeks. Our Aquaprobe multiparameter water testing devices are designed for use in the field, and some of the models are designed for long term deployment. Using a fluorometer in-situ eliminates the cost of lab analyses, and is suitable for both continuous-flow monitoring or discrete sample analyses.

There are many applications for rhodamine testing. You can use rhodamine dye and fluorometers in surface water, wastewater and groundwater. In surface water you might study irrigation uptake by plants, spill mapping and response and mixing zone identification and characterisation. In wastewater, rhodamine testing is used to monitor sewer overflows and for hydraulic characterisation of wastewater treatment facilities for operations or environmental purposes, for example. For groundwater, you might use a rhodamine sensor to monitor aquifer hydraulics, trace pollution plumes, and tag and trace herbicide migration and dispersion.


For the most accurate measurements of the concentration of rhodamine in water it’s also necessary to measure other parameters; temperature and conductivity. It may also be ideal to measure turbidity, because this can cause interference to the fluorometer.

Aquaread’s water rhodamine meter

Aquaread’s water rhodamine analysis meter takes the form of a submersible fluorometer that provides excitation at a wavelength of 540nm, and detects resultant fluorescence above 570nm. Our rhodamine sensor is an optional optical electrode that works with all of our Aquaprobe equipment. Our rhodamine probe equipment measures in the range of 0 – 500 ug/L (ppb) and data is logged with a resolution of 0.1 ug/L.

Before injecting Rhodamine into a body of water, check the Rhodamine msds.

Get into monitoring with Aquaread

If you would like any more information about TDS meters and other total dissolved solids testing equipment, or water quality monitoring in general, please Contact Us. Click here to see our product range.