Model 420 & 425 Flame Photometer
425 91 001
Issue 22
1
st
December 2016
ECN 1410 & 1932
- 18 -
2
Installation
2.1
Location
WARNING
Under no circumstances install the Model 420/425 beneath
overhanging cupboards. There must be at least 1 metre of clear
space above the chimney.
For optimum performance, this instrument should be installed in
accordance with the following conditions: -
2.1.1 The environment must be clean and free from dust.
2.1.2 The instrument must be placed on a strong, level worktop, free from
vibration. The Model 420/425 requires approximately 500mm x
500mm of bench space, which includes an area in front for solutions
and clearance at the rear for fuel and air tubing, with clear access to
the mains supply switch.
2.1.3. Avoid sites that expose the instrument to direct sunlight or draughts.
2.1.4. To meet the specification the ambient temperature must be within
the range +10°C to +35°C and the maximum relative hum idity must
not be more than 85%, non-condensing.
2.2
Services Required
Electrical Supply
An A.C. supply between 90V and 240V ±10%, at 50Hz or 60Hz, is required for the
Model 420 and 425. The instrument is powered from an external power supply,
which will accommodate these voltages without any need to adjust the instrument.
Fuel
A supply of Propane, Butane or Propane/Butane mixture regulated at the cylinder
to 2.1kg/cm
2
(30psi), flow rate at least 0.4 litres per minute.
(NB. Propane only, gives the best results for Ca on the Model 425).
Primary regulators to fit cylinders are available from Sherwood Scientific, regulators
are available as optional accessories, refer to Section 9.2.
Air
A supply of clean, dry, oil-free air at 1kg/cm
2
(11psi), flow rate 6 litres per minute. A
suitable air compressor is listed in Section 9.2.
Waste Container
A sink or waste container sited to the right of the instrument will ensure the
minimum length of waste tubing. Do not use a waste container with high sides, as
this will cause the drain tube to be lifted above the level of the constant head drain.
