TDS Meter Photocolorimeter & Flame Photometer Lab Equipment Manufacturer, Supplier and Exporter in India

Eleven instruments are listed here, TDS-0001 to TDS-0011, and they are three quite different things sharing one listing: three flame photometers, which burn a fuel gas; four photocolorimeters, which measure absorbance through a filter; and four total dissolved solids meters, which are conductivity meters with a conversion applied. The three groups have almost nothing in common as purchases. The flame photometers are the ones that change what your laboratory needs, because a gas supply comes with the instrument, and that section is first.

What is in the range

Flame photometers: the gas supply is part of the purchase

A flame photometer burns fuel gas continuously while it is in use, so buying one commits the laboratory to a gas supply, its controls and its paperwork. Settle all of this before the order:

• Which fuel, at what pressure, and how much. Ask the gas, the regulated supply pressure the instrument needs and the consumption, so the cylinder size and change frequency can be planned.
• Air supply. Ask whether air comes from an integral compressor or must be provided separately, and if separately, the pressure and flow and whether it must be oil-free and dried, because an oily or wet air supply spoils the flame and the readings.
• Cylinder storage and restraint, sited to your own rules, with cylinders secured upright and not in the laboratory where that can be avoided; and the length and material of the run from cylinder to bench.
• Ventilation and extraction over the instrument, since the flame consumes air and the exhaust carries combustion products and whatever was aspirated into it.
• Leak testing before every session, a shut-off valve the operator can reach without leaning over the instrument, and a flame arrestor where the supplier specifies one. Ask what the instrument does on flame failure, and whether it has a flame-out cut-off that closes the gas.
• The right extinguisher at the bench, and a written start-up and shut-down sequence, because the order in which gas and air are turned on and off is the main thing that goes wrong with this instrument.

On the instrument itself, ask which elements it determines and which filters are supplied, the linear range and detection limit for each element, and the repeatability. Ask whether single or dual channel makes a difference to your work: a dual-channel instrument reads two elements at once, which halves the work where sodium and potassium are both wanted, which is most clinical and soil and fertiliser work. Ask what calibration standards are needed, whether any are supplied, their shelf life, and the price of replacements, because standards are the recurring cost and a flame photometer is recalibrated every session. Ask also about the aspiration system: the nebuliser and burner need cleaning, so ask how they are removed and cleaned and what a replacement costs.

Photocolorimeters: filters, cuvettes and what the instrument cannot do

A filter photocolorimeter passes light through a coloured filter and a sample and measures what gets through. It is a robust and inexpensive instrument and it is the right choice for routine determinations where the method specifies a filter wavelength. Two honest limits are worth stating: it selects a broad band rather than a narrow wavelength, so it cannot resolve overlapping absorbances the way a spectrophotometer can, and it can only work at the wavelengths of the filters fitted. So the first question is which filters are supplied, with their nominal wavelengths, and whether the set covers every method you run; the difference between the five-filter and eight-filter codes here is exactly that.

Then ask: the cuvette type, path length and whether cuvettes are supplied, with the price of replacements, since they are both consumable and easily scratched; the absorbance range and resolution, and the photometric accuracy; whether the instrument reads absorbance only or also transmittance and concentration, and if concentration, how the factor is entered; the stability and warm-up time, which matters because a drifting instrument has to be re-zeroed constantly; and what auto zero means on TDS-0006, since that is the only stated difference between it and the others. For the microprocessor-based unit, ask whether it stores methods and whether results can be printed or exported. A colorimeter cannot be put into service without cuvettes and without the standards for the method, so order all three together.

Total dissolved solids meters: what the number actually is

These four are conductivity meters that display a dissolved solids figure, and it is worth being clear what that means. The instrument measures conductivity and multiplies it by a factor to estimate dissolved solids; the factor depends on which salts are present, so the figure is an estimate and two waters of the same conductivity but different composition will give the same reading and different true solids content. For drinking water screening and for watching a process that does not change composition, that is perfectly adequate. For a reported analytical result, the reference method is evaporation and weighing.

So ask: what conversion factor the meter uses and whether it can be changed; the range and resolution; whether temperature compensation is automatic, which matters because conductivity changes about two per cent per degree Celsius, and TDS-0009 states that it is; the calibration standards needed and whether supplied; and for the pocket and portable units the ingress rating, battery type and life. The same questions in more detail, including the cell constant, are under Conductivity and Dissolved Oxygen Meters, which carries the conductivity meters themselves.

Also worth confirming

This listing mixes three unrelated instrument families under a name that describes only one of them, so quote the code and say which instrument you mean. Ask for the manual and the method notes, the calibration standards and cuvettes to order with the instrument, the supply voltage, frequency and plug type for your country, the local service and calibration arrangement, whether a calibration certificate is supplied, and the warranty. Any accuracy, range or detection limit quoted is confirmed in writing on the quotation; ask for the conditions behind it.

Related ranges on this site

Conductivity and dissolved oxygen meters are under Conductivity and Dissolved Oxygen Meters. The water for standards and dilutions is under Water Distillations and Stills, weighing under Lab Balances and Scales, digestion for nitrogen and chemical oxygen demand under Kjeldahl Digestion and Distillation Unit, separation under TLC and Electrophoresis Apparatus, and sterilisation and incubation under Autoclaves, Sterilizers and Shakers.

Request a quote

Say which determinations you run and on what sample type. For example a dual-channel flame photometer (TDS-0002) with the fuel and air requirement, the consumption, the elements and filters, the standards and the flame-out cut-off stated in writing; or an eight-filter photocolorimeter (TDS-0004) with the filter wavelengths listed and cuvettes included. Contact Ray Export for specifications, prices and lead times.

Frequently asked questions

Do I need a gas supply for the flame photometers TDS-0001 to TDS-0003?

Yes. A flame photometer burns fuel gas continuously while it is in use. Before ordering, ask which fuel, the regulated supply pressure and the consumption, so cylinder size and change frequency can be planned. Ask whether air comes from an integral compressor or must be provided separately, and if separately, whether it must be oil-free and dried, since oily or wet air spoils the flame and the readings. Plan cylinder storage and restraint away from the laboratory where possible, extraction over the instrument, leak testing before each session and a shut-off valve the operator can reach.

Should we choose a single-channel or dual-channel flame photometer?

TDS-0001 is single channel, TDS-0002 dual channel and TDS-0003 microprocessor based. A dual-channel instrument reads two elements at once, which halves the work where sodium and potassium are both wanted, and that covers most clinical, soil and fertiliser work. If you only ever determine one element, single channel may be enough. Either way, ask which elements it determines and which filters are supplied, the linear range and detection limit for each element and the repeatability, and have those figures confirmed in writing on the quotation.

How do the four photocolorimeters TDS-0004 to TDS-0007 differ?

TDS-0004 has eight filters, TDS-0005 five filters, TDS-0006 is listed as auto zero and TDS-0007 has eight filters and is microprocessor based. Filter count matters because a filter colorimeter can only work at the wavelengths of the filters fitted, so ask for the nominal wavelengths and check the set covers every method you run. Auto zero is the only stated difference for TDS-0006, so ask what it means in practice. For TDS-0007, ask whether it stores methods and whether results can be printed or exported.

Can a photocolorimeter do the job of a spectrophotometer?

Not for every job. A filter photocolorimeter selects a broad band rather than a narrow wavelength, so it cannot resolve overlapping absorbances the way a spectrophotometer can, and it works only at the wavelengths of its fitted filters. It is a robust instrument and the right choice for routine determinations where the method specifies a filter wavelength. It cannot be put into service without cuvettes and the standards for the method, so order all three together, and ask the cuvette type and path length, since cuvettes are consumable and scratch easily.

Is the reading from a TDS meter an analytical result?

It is an estimate. TDS-0008 to TDS-0011 measure conductivity and multiply it by a factor to estimate dissolved solids, and that factor depends on which salts are present. Two waters with the same conductivity but different composition give the same reading and different true solids content. For drinking water screening, or for watching a process that does not change composition, that is adequate. For a reported analytical result, the reference method is evaporation and weighing. Ask what conversion factor the meter uses and whether it can be changed.

Which of the TDS meters has automatic temperature compensation?

TDS-0009, the waterproof pocket meter, states automatic temperature compensation. That matters because conductivity changes by about two per cent per deg C, so an uncompensated reading moves with sample temperature. For TDS-0008 (pocket), TDS-0010 (portable) and TDS-0011 (bench), ask whether compensation is automatic, along with the range and resolution, the calibration standards needed and whether they are supplied, and for the pocket and portable units the ingress rating, battery type and battery life.

Key takeaways

• Three families, one listing: flame photometers (TDS-0001 to 0003), photocolorimeters (TDS-0004 to 0007) and dissolved solids meters (TDS-0008 to 0011) are separate purchases.
• The flame photometer brings a gas supply: fuel, air, cylinder storage, extraction and a written start-up and shut-down sequence are part of the order.
• Dual channel halves the work where sodium and potassium are both wanted, as in most clinical, soil and fertiliser work.
• A colorimeter works only at its filter wavelengths: get the nominal wavelengths of the five- or eight-filter set before choosing a code.
• A TDS figure is an estimate from conductivity and a factor; evaporation and weighing is the reference method for a reported result.
• Order consumables with the instrument: calibration standards for every unit, and cuvettes for the photocolorimeters.

About this page

Ray Export is a manufacturer and exporter of laboratory, scientific and educational equipment based at Plot No. 449, HSIIDC Industrial Area, Saha, Ambala, Haryana 133104, India. Enquiries: [email protected], +91-9817319615.

Written by Palak Mall, Senior Content Writer. Technically reviewed by Arvind Kumar, Lab Equipment Specialist, 12+ years in laboratory and testing instrumentation. Last updated: 18 October 2026.

Specifications on this page are confirmed in writing on the quotation; for certificates, contact us for the latest copies of the relevant certificates. No price is quoted on this page. Listing notes: this range mixes three unrelated instrument families under one name; TDS-0004 and TDS-0007 are both eight-filter units distinguished only by the microprocessor; and auto zero is the only stated difference for TDS-0006.