The Model 420Cs is Sherwood’s newest addition to the Flame Photometer product line. Evolved from the well-established Model 420, the Model 420Cs provides a precision (%CV) ≤ 0.5, now achievable with all new Dual Channel models: i.e. the Model 420 & Model 425.
Unique to the Model 420Cs is the addition of a Caesium reference channel. This enables the analyst to work with Caesium or Lithium as an internal reference. The Model 420Cs’ additional internal reference option provides greater flexibility; operators have the ability to choose the internal reference element based on the sample matrix considerations or existing procedures developed for discontinued instrumentation such as the IL 943 Flame Photometer.

Highlights:
• Onboard firmware with blanking, calibration and sample routines.
• Simultaneous measurement of two out of three elements: Sodium, Potassium and/or Lithium.
• Linearised Sodium response over the expected clinical Sodium concentration range (1 in 200 sample dilution).
• Internal reference facility for improved precision.
• Automatic flame ignition and optimisation.
• Safety features including optical flame and low air pressure detection for fuel gas shut off.
• Two digital displays for calibration and analysis of data of each channel; analogue outputs for use with chart recorders and some online analysers.
• A “no tools” maintenance approach allowing easy access to the mixing chamber and burner assembly.
• RS232 for data output to a serial printer.

Features:
• Five element (Na, K, Li, Ca, Ba)
• Single channel Analogue Flame Photometer
• Ergonomic design with front loading, unobstructed sample work area, with removable tray for easy cleaning
• With the ease of use resulting from auto ignition and flame optimization.
• Peak picker for presenting unambiguous readings
• With the selected filter indicator
• Safety features including fail-safe flame detection and shut off, with low air pressure indicator
• High sensitivity with fine manual control of air, and stable flame design
• And ease of maintenance and storage
• Separate pneumatic and electronic pods
• Small footprint (20 x 30cm)
• Easy to remove and clean filter stick

Available In Three Formats:
• 36000009 – M360 5-ELEMENT FLAME PHOTOMETER – Propane/Butane
• 36000109 – M360 5-ELEMENT FLAME PHOTOMETER – Natural Gas
• Both the above are supplied with individual1000 ppm (mg/l) calibration concentrate solutions
• 36000209 – M360C 5-ELEMENT FLAME PHOTOMETER – Propane/Butane
• The M360C is provided with a mixed calibration concentrate 140.0/5.00/1.50 mmol/l Na/K/Li

It is important to order the correct part number to ensure fuel gas compatibility. Detector response in the 360C is “linearized” when the Sodium filter is selected; 
the 360C specification – see below – assumes samples are diluted as indicated.

All three Models of 410 Flame Photometer come with a preloaded filter stick which houses a maximum of three element filters. The filter stick is easily removed and replaced within the chimney housing (no tools required) and as such it is a relatively simple operation to introduce alternative element-specific filters.
Filters available for use with all Model 410’s include:
• Sodium, Potassium, Lithium, Calcium, Barium, Strontium, Rubidium, and Caesium; the most extensive range available from any Flame Photometer Manufacturer.

The Model 410 Classic Flame Photometer (410 00 009) comes with Sodium, Potassium, and Calcium filters. The “Classic” design is, in essence, the one developed by Corning some 30 years ago. We still manufacture this highly successful unit due to popular demand. The Model 410 Classic Flame Photometer has Sodium, Potassium, and Calcium NIST traceable 1000 ppm standard concentrates for each of those analytes (6 x 100 ml).

We have expanded the Model 410 Classic’s utility by introducing of the:
• Models 410 Industrial and 410 Scientific Flame Photometers; both come with a Digital Interface fitted as standard. The Digital Interface allows connection to a serial printer or computer for result collection.
• The Model 410 Industrial Flame Photometer (410 00 209); Flame Photometry is the technique of choice for the measurement of Sodium, Potassium, and Calcium in all sample types in Mineral Extraction, Oil Industry, Paper Industry, Pharmaceuticals, Soil Analysis, Utilities, Food & Beverage, Chemical Manufacture and Fertilisers. The Model 410 Industrial Flame Photometer with digital output, for printer or PC connection, also has Sodium linearisation capability to allow higher concentrations of Sodium (to 20 ppm) to be directly measured using a single point calibration. That facility can be switched on or off according to the operator’s preference or protocol for Sodium determinations. The Model 410 Industrial Flame Photometer has Sodium, Potassium, and Calcium-specific filters and NIST traceable 1000 ppm standard concentrates for each of those analytes (6 x 100 ml).
• Model 410 Scientific Flame Photometer (410 00 309); For biological samples, Flame Photometry is the most sensitive and robust method for the determination of Sodium, Potassium, and Lithium. The Model 410C Flame Photometer is delivered with Na, K, and Li filters pre-fitted and an appropriate multi-element calibrator in mmol/l. (1 x 100ml). The Model 410 Scientific instrument is also fitted with a Digital Interface and Sodium linearisation facility allowing direct, straight-line, calibration of clinically significant concentrations of Sodium, as well as Potassium and Lithium, following suitable dilution. (Sherwood’s Model 806 Continuous Flow Diluter, used together with the Model 410 Scientific Flame Photometer, gives nominal sample dilution ratios of 1:200 and 1:50. It has been designed to give consistent dilution of calibrator and samples to the Flame Photometer).

Both Model 410 Industrial and Model 410 Scientific Flame Photometers can be further enhanced by the use of Sherwood’s Model 410 BlueNotes software (410 66 000) and Model 865 Autosampler (865 00 009). Fully integrated and automated systems are possible, even for the Model 410 Classic Flame Photometer via our Update and Automate Modules and packages. See BlueNotes 410 Software in Flame Photometer Accessories on the main Flame Photometer product page.

The Model 420C Flame Photometer was developed from the Single Channel Model 410 Flame Photometer, with the objective of improving productivity and analytical performance, when measuring Sodium and Potassium.

It is available for order against two part numbers:
• The 420C (475 42 000) is delivered as standard with a mixed calibration concentrate containing 140.0, 5.00, and 1.50 mmol/l of Na, K, and Li.
• The M420 Industrial (475 42 100) is delivered as standard with individual 1000ppm calibration concentrates for Na, K, and Li.

Dual Channel operation, allows both Sodium and Potassium to be calibrated, measured, and displayed simultaneously. The Model 420 Flame Photometer retains many of the Model 410’s attributes: ease of use, ease of maintenance, and stable flame design, and is enhanced with auto flame optimization, internal standard referencing, and on-board firmware to achieve significant improvement in sample throughput and precision. The time taken to set up and calibrate the instrument is much reduced; achieved by automatic ignition and optimization of the flame conditions. The analytical performance is improved using a Lithium Internal Reference signal which compensates for fluctuation in flame conditions. The internal reference feature (Reference Mode) can be turned off if required. Readings on both channels are linear over the working range of the Model 420 Flame Photometer. There are several monitoring and control functions included in the firmware; thus, measurements can only be made after blanking and calibration.

The Model 420 Flame Photometer can operate in Continuous or Peak mode. In Continuous mode, the instrument displays the current value on each channel and through the analog ports. An instantaneous reading can be printed at any time. In Peak mode, the Model 420 Flame Photometer automatically detects a stable reading, following sample introduction, for transfer to a printer or computer, and the display is frozen until the next sample is introduced.
The Model 420 Flame Photometer has RS232 output for printer or computer connection and is compatible for standalone use with Sherwood’s Model 860 Autosampler; providing unattended sample analysis. The system may be used with the Model 805 Continuous Flow Diluter, again in conjunction with or without the Model 860 Autosampler.

The Model 425 Flame Photometer (475 42 500) expands upon the capability of the Model 420 Flame Photometer with the addition of a detector and filter assembly specific for Calcium determination. It also offers a “301 mode” feature which allows connection to a few of the more popular continuous flow systems.
The Model 425 defaults to measurement with Lithium Internal Reference. This should be added to the blank, calibration standards, and samples such that they all contain the same concentration of Lithium; i.e. ~ 100 ppm. The Model 425 is supplied with Li solution 001 56 622. This should be diluted 1:10 with distilled water and the resulting solution used as the blank to dilute the calibration standard and samples. Sherwood Scientific can supply a 3 Molar solution of Li (001 56 603; 6x 100 ml) which when diluted at 1:200 will give the optimum Lithium internal reference level. This is cheaper than using the 001 56 622 and is designed to be used with the Model 805 Dilutor where it is simultaneously diluted and mixed to the correct dilution for blank, calibrators, and samples.

The Model 425 Flame Photometer has RS232 output for printer or computer connection and is compatible with our Model 860 Autosampler for unattended sample analysis. The Model 425 may be used with the Model 805 Continuous Flow Dilutor, again in conjunction with or without the Model 860 Autosampler and with or without BlueNotes 420 software.
A new optical arrangement implemented in 2018 gives improvement to the hitherto-known issue of Sodium interference with Calcium determinations.

Previously reported interference was around the 4% mark and interference in newly manufactured units is now reduced to less than 1% for samples containing equal concentrations of both Sodium and Calcium.
• Onboard firmware with blanking, calibration, and sample routines.
• Simultaneous measurement of two of four elements: Sodium, Potassium, Calcium, and/or Lithium.
• Linearised Sodium response over the Sodium concentration range 0.5 to 20 ppm
• Internal Reference facility (Lithium) for improved precision.
• Automatic flame ignition and optimization.
• Safety features including optical flame and low air pressure detection for fuel gas shut off.
• Two digital displays for calibration and analysis of data of each channel; analog outputs for use with chart recorders and some online analyzers.
• A “no tools” maintenance approach allowing easy access to the mixing chamber and burner assembly.
• RS232 for data output to a serial print

Lithium Internal Standard:
The Model 425 defaults to measurement with Lithium Internal Standard. This should be set to 100 ppm Li and added to the blank, calibration standards, and samples.
The Model 425 is supplied with Li solution 00156622. This should be diluted 1:10 with distilled water and the resulting solution used as the blank to dilute the calibration standard and samples.
Sherwood Scientific can supply a 3 Molar solution of Li (00156603; 6x 100 ml) which when diluted at 1:200 will give the optimum Lithium internal standard. This is cheaper than using the 00156622 and is designed to be used with the Model 805 Diluter where it is simultaneously diluted and mixed at the correct dilution to the standards and samples.