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Lovibond’s Comparators vs Photometers – which to choose?

Lovibond have been providing kits for water analysis or colour measurement for more than 130 years. Their core focus is pool, environmental and industrial water analytics along with transmission and reflection colour measurement. Their emphasis is on easy to use equipment through rapid visual tests, photometers and spectrophotometers.

Colourimetric testing is a widely used method. In water testing, a chemical reagent (eg. DPD for chlorine determination) is added to a sample of water. The intensity of the colour is then measured to determine the concentration of the chemical present (eg. Chlorine), the concentration of the parameter can then be determined either using a Comparator & Disc, (visual system) or a photometer (electronic/digital) system. The following provides an overview of key comparators and photometers available from Lovibond.

Comparators

Lovibond offers four types of  comparators:

CHECKIT Comparator – The CHECKIT Comparator is a compact and handy colourimetric unit which is suitable for both mobile and static analysis. Available with a generous number of different colour scales, CHECKIT provides the basis for a comprehensive, easy-to-use colourimetric analysis system.

CHECKIT Disc – Each CHECKIT Disc contains a continuous colour scale which makes it possible to achieve an exact colour match between the colour standard and the sample (opposite). CHECKIT Discs are specially manufactured from selected materials to retain colour stability over a long period and guarantee reliable, reproducible measurement results.

Applications portable water treatment (e.g. Drinking Water), pool water, laboratory and field testing.

The Comparator 2000+ is an easy-to-use, entry-level colour measurement system that compares the colour of the sample directly against the colour of glass in a disc. All you need to do is rotate the disc to get the closest result on the scale.

Test Discs – The glass discs provide stable fade-free colour standards as well as being resistant to chemicals and scratchproof. They comply with international standards such as ISO 7393/2.

Applications portable water treatment (e.g. Drinking Water), pool water, laboratory, field testing, research centres and universities.

The Lovibond EComparator Pt-Co provides an easy way to replace the subjective visual colour comparison with an objective and accurate electronic measurement, without sacrificing the visual view. The display (opposite) allows onscreen viewing of the colour and a numerical display.

The EComparator Pt-Co is supplied with certified glass and liquid reference standards allowing quick and simple validation. The instrument is equipped with an integrated light shield to protect the sample from ambient light and a flexible path length and cell (plastic or glass) for different applications.

Industrial applications include chemical, food and beverage,  oil and gas, and pharmaceutical.

The Model F is a benchtop comparator designed to optimise the use of Lovibond’s glass filters to meet the requirements of different applications. This comparator is set to national and international standardising bodies which specify the instrument in their official methods for colour measurement.

Industrial-based applications include for beer, malts and caramels, edible oils and fats,  food and beverage,  and petroleum oils and waxes.

Here are some pointers to help you decide on the best comparator option for your application:

  • Using a comparator visual system you can obtain a good estimation of the chemical concentration. The accuracy of this type of system is dependent on the human eye and lighting conditions, therefore, subjectivity is a part of this analysis.  To improve on this a lighting unit can be used with some comparators in buildings where there is no natural lighting or where there is changing light conditions.
  • The comparator system is based on visual comparison with coloured filters, which are calibrated to allow direct measurement of concentration levels.  The plastic discs used with the CHECKIT Comparator are lower cost, however slightly less accurate and durable than the glass discs used with the Comparator 2000+. Both systems offer a wide range of discs to all key chemicals required for water testing with around 400 different discs for measuring various parameters, i.e. Ammonia, Chlorine, pH amongst others.
  • Key benefits with these systems are a user-friendly and robust instrument useful for both field and laboratory use.

Photometers

In addition, there are four different types of photometers:

The MD 100 photometer is a convenient choice for testing up to 14 parameters on a single instrument.  The instrument has a simple user interface and is constructed for field use.  Several industry-specific versions are available, for example boiler and cooling water analysis amongst others. All MD100’s come with a storage capacity of around 16 data sets.

The MD 110 photometers are identical to the MD100 with the addition of Bluetooth functionality, an app for mobile devices is available as well as PC software with a dongle. The results can be transmitted to external devices via the Bluetooth interface for quick evaluation and processing so that all data can be evaluated and assigned directly on site.

Applications portable water treatment (e.g. Drinking Water), pool water, laboratory and field testing.

The MD 600 series of photometers are ideal for testing waste, drinking or industrial water samples for science or research applications.  These photometers have more than 100 pre-programmed test methods installed and have the analytical properties of a laboratory photometer with a storage of around 500 data sets. Reliable and fast testing is guaranteed, due to long-term stable LEDs and their interference filters. The MD610 and MD640 have a Bluetooth interface for mobile data management via an app.  The MD640 has the additional capability of measuring PTSA and Fluorescein.

Applications portable water treatment, food testing, laboratory and field testing.

The MultiDirect is a benchtop photometer which provides a large graphic display combined with an acid and solvent resistant touch-sensitive keypad with audible feedback.  It is pre-programmed with a wide range of methods which are updateable through the internet. In addition, it can store a larger amount of data (approx. 1000 data sets with date, time and registration number) compared to the MD 100 and MD600 series.

Applications designed for laboratory-based testing in the chemical, food and beverage, marine, municipalities, NGO, oil and gas, pharmaceutical, and power and energy industries.

The new Scuba II is an easy to use, floatable, waterproof photometer specifically designed for private pool owners to enable them to test their pool water. The Scuba II  works intuitively measuring the most important pool parameters of free chlorine, total chlorine, bromine, pH, alkalinity-m and cyanuric acid provides immediate results.

Application private ower pool testing.

 

Should visual colour comparison not provide adequate accuracy and reproducibility then a photometric system would be preferable. The MD 100 and Scuba II would be the entry-level photometers with the MD600 required where larger ranges of analytes need to be assessed. The benefits of the entry-level photometers are the ability to obtain cost-effective accurate readings for select analytes without the cost of additional features.

 

For further information on Lovibond check out our web listing or contact us by phoning 01954 233110 or email us at sales@camlab.co.uk.

 

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