Specification and Services.

Purpose.

To measure the concentration of a standard Na.Cl. aerosol both before and after it has passed through an air filtration device.

Sensitivity.

Better than 10ng/m³ giving a minimum detectable penetration of less than 0,0005%.
With a challenge aerosol of 13mg/m³.
Response time 400ms.
Band by-pass filter better than 0.3nm

Maximum Concentration.

Continuous indication of mass concentrations up to 3mg/m³, but for short periods up to 20mg/m³ if calibrated to this level.

Sample Flow Rate

2 l / min +/- 0.1 l / min ( Fixed with electric pump, adjustable with venturii suction.)

Inhalation Sensor

Accuracy: +/- 0.5% Full scale (0.5mb FS) Max pressure / vacuum 140 KPa
Operating temp 0 to 50°C

Pulsed sampling switching valves

• Response time 30ms
• Rated for 26Hg vacuum
• Max operating temp 70ºC
• Minimal dead volume
• Protected by Coolcube? technology for continuous operation.

Air Supply Minimum flow 50 l/min@ 5 bar

Electrical Power 230Vac 50 or 60 Hz. Single phase, specified with order.

Dimensions

1.58 long X 0.5m high X 0.29 deep

Weight

74Kg

Finish

Case:- Colour mid grey.
Front Panel:- semi Gloss White.

Principle of Operation.

The photometer is initially set up using a high grade (HEPA) air filter, through which the vacuum pump pulls a 2 l / min sample of ambient air past the hydrogen flame to give a clean air reference point to the detector system, any sample of sodium chloride aerosol detected above this reference of 50 µA. can be related to the calibration graph. When NaCl. is burnt it generates a specific sodium yellow with a wavelength of 589 nm.

Between the flame and the PMT are neutral density filters [NDF?s], these are darken glass slides of known value, and an interference filter allowing only the sodium wavelength to pass. The N.D.F.?s are used to prevent an overload of the PMT when higher concentrations of NaCl. are burnt and to keep the meter reading on scale.

For aerosol concentrations up to approx 0,13mg/m³ the response is linear, above this level there is some light absorption by the flame, hence the curve on the calibration graph.

The interference filter dedicates the photometer to sodium light therefore any other substances that do not burn with a sodium light, are ignored in the final analysis of the penetration / efficiency of the test device.

The Type 1300 incorporates a PC which records data, generates graphs and tabulates results.

Full specification on request as the PC and software continues to evolve.