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    Model 420

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    Product Overview

    The Dual Channel Model 420 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 Model 420C (475 42 000) is delivered  with a mixed calibration concentrate containing 140.0, 5.00 and 1.50 mmol/l of Na, K and Li.

    The Model 420 Industrial (475 42 100) is delivered with individual 1000 ppm calibration concentrates for Na, K and Li.

    Dual Channel operation, allows both Sodium and Potassium to be blanked, 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 optimisation, internal reference 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 optimisation 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 analogue 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 Dilutor, again in-conjunction with or without the Model 860 Autosampler.

     

     

    420 Industrial (475 42 100) Specification

    Range Displayed

    Na 0.00 – 9.99; 10.0 – 199.9

    K 0.00 – 9.99; 10.0 – 199.9

    Li 0.00 – 9.99; 10.0 – 199.9

    Sample concentration entering aspiration

    Na 0.5- 20 ppm

    K 0.5- 20 ppm

    Li 0 – 20 ppm


    Specificity

    Na, K & Li Interference is < 0.5% value of element
    under analysis. 

    Linearity
    (To be tested without Li Internal Reference)
    For Na, K, & Li with appropriate solution concentration, within the limits shown under Sample Concentrations (above), set at 100 will read 48-52 at midpoint ( Nominal 50).

    Dimensions

    510mm x 390mm x 345mm 9.5 Kg  Net
    730mm x 450mm x 450mm 16.5 Kg  Packed

    Sensitivity
    Minimum Detection level =3 x noise
    Na 20 ppb
    K 20 ppb
    Li 50 ppb

    Minimum Concentration to display 100 units

    Na 0.5 ppm

    K 0.5 ppm

    Li 0.5 ppm


    Reproducibility (K=10ppm 20 aliquots from single sample)

    With Li Reference in operation < 0.5% CV

    Without < 1.0% CV

    Speed of analysis

    Variable (sample every 15-60 seconds) at user option

    Aspiration rate

    3-6 ml/min

    Minimum sample requirement

    1.5ml (Diluted sample)

     

     

    Model 420C (475 42 000) Specification

    Sodium measurement

    Sodium is highly prone to self-absorbance in the flame above a concentration of 10 ppm. Linearising

    software has been incorporated in the Model 420. At the normal clinical level of sodium 140mmol/l even

    diluted by 1:200 exceeds this concentration.

    (NB. 140 mmol/l x 22.98 A.W.(Na). =3217.2 ppm x 1/200 = <16 ppm).

    Lithium Internal Reference

    The Model 420 defaults to measurement with Lithium Internal Reference

    The Model 420 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 and to dilute the calibration standard and samples.

    Sherwood Scientific can supply a 3 Molar solution of Li (001 56 603; 6 x 100ml), which when diluted 1:200 will give the optimum Lithium internal reference level in Blank, Calibrator and samples. This is more cost effective than using  001 56 622 and is designed to be used with the Model 805 Dilutor where it is simultaneously diluted and mixed at the correct dilution with calibration standards and samples.

    Range Displayed

    Na 0.00 – 9.99; 10.0 – 199.9

    K 0.00 – 9.99; 10.0 – 199.9

    SAMPLE CONCENTRATION entering aspiration

     

    Element ppm mg/l meq/l
    Na 0.5 – 20 0.5 – 20 0.022 – 0.87
    K 0.5 – 20 0.5 – 20 0.013 – 0.5
    Li 0 0 – 20 0 0 – 20 0.0 – 2.9

    Specificity
    Na, K & Li Interference is < 0.5% value of element
    under analysis.
    Linearity
    (To be tested without Li Internal Standard)
    For Na,, the 00156100 Standard diluted 1:200 set at 140 will read 68 – 72 at midpoint (Nominal 70).
    For K, the 00156100 Standard diluted 1:200 set at 5.0 will read 2.40 – 2.60. (Nominal 2.50).
    Dimensions
    510mm x 390mm x 345mm 9.5 Kg Net
    730mm x 450mm x 450mm 16.5 Kg Packed

    Sensitivity
    (i) Minimum Detection level=3 x noise

    Element

    ppm

    mg/l

    meq/l

    Na

    0.02

    0.02

    0.0009

    K

    0.02

    0.02

    0.0005

    Li

    0.05

    0.05

    0.007

     

    (ii) Minimum Concentration to give 100 units on display

    Element

    ppm

    mg/l

    meq/l

    Na

    0.5

    0.5

    0.022

    K

    0.5

    0.5

    0.013

    Li

    0.5

    0.5

    0.072

     

    Reproducibility (K=10ppm 20 aliquots from single sample)
    With Li Reference in operation < 0.5% CV
    Without < 1.0% CV
    Speed of Analysis

    Variable (sample every 15-60 seconds) at user option

    Aspiration rate

    3-6 ml/min

    Minimum Sample Requirement

    1.5ml (Diluted sample)ariable (sample every 15-60 seconds) at user option

     

     

     

     

     

    Accessories

    420 BlueNotesTM software (420 66 000)

    Supplied free of charge with all new Model 420 and Model 425 Flame Photometers.

    With the Model 420 BlueNotes software package you can:

    • Use real names and sample numbers in your reports
    • Perform Multipoint calibrations with curve fit
    • Monitor all three (Model 420) or all four (Model 425) detector outputs simultaneously
    • Select Lithium or Potassium as the internal reference material
    • Save calibration curves
    • Save methods
    • Archive results
    • Prepare and print professional reports
    • Use Automatic Peak Selection facility to assess stability of readings
    • Automate analyses with addition of the Model 860 Autosampler

     Everything is visible on one operational page.

    (Requires PC (not supplied) with Windows 7 or later operating software)

    Note:  If you require software that allows you to work in compliance with regulations such as CFR 21 Part 11, you need Regulated BlueNotes 420 software (420 66 100)