ADVANTAGES

The 1412 is also built for speed, portability and versatility. In fact, the measurement cycle for 5 gases and water vapor can be as short as 40 seconds. Variable flushing and sample integration provide added flexibility, allowing you to choose between speed and sensitivity. With a list of over 20 optical filters, the 1412 can be calibrated for hundreds of different applications.  For multi-point applications, the 1412 can be combined with A Multipoint Sampler

COMPUTER COMPATIBILITY

The 1412 comes standard with PC-based software. Install it on your PC and you can use it to set-up all measurement parameters. Data collected can be presented in graphic formats and in tables. Statistical analysis can be made from any graphical or numerical window. Data can be exported into spreadsheet or word processing programs with ease. The 1412 also functions effectively as a stand-alone unit.

SPECIFICATIONS

MEASUREMENT TECHNIQUE: Photoacoustic infra-red spectroscopy
RESPONSE TIME: (including chamber flushing) is dependent on the sample integration time (S.I.T.) and the flushing time defined. The fastest response time for one gas is 13 s and for 5 gases and water vapor 40s, but see the examples below: (including chamber flushing) is dependent on the sample integration time (S.I.T.) and the flushing time defined. The fastest response time for one gas is 13 seconds; and for 5 gases and water vapor 40 seconds.
MEASUREMENT UNITS: (1412PC) - mg/m³, g/m³, u/m³ ppm, vol%, ppb
REPEATABILITY: 1% of reading
Zero Drift: Typically ± Detection limit per 3 months
Influence of temperature : ± 0.5% of detection limit / °C
Influence of pressure : ± 0.5% of detection limit /mbar
A concentration of 100x detection limit was used determining these specifications:
Repeatability: 1% of measured value
Range Drift: ± 2.5% of measured value per 3 months
Influence of temperature : ± 0.3% of measured value/° C
Influence of pressure : -0.01% of measured value/mbar
Reference conditions:
Measured at 20° C 1013 mbar, and relative humidity (RH): 60%
Measured at 1013 mbar, and RH: 60%
Measured at 20° C and RH: 60%
Measured detection limit is @ 5s S.I.T.
INTERFERENCE:
The 1412 automatically compensates for temperature & barometric pressure fluctuations in its analysis cell, and can compensate for water vapor in the air sample. If an optical filter is installed to measure a known interferent, the 1412 can cross-compensate for the interferent
DATA STORAGE CAPACITY: (for stand-alone) Dependent on the number of gases being measured. Sufficient for a 12-day monitoring task, monitoring 5 gases and water vapor every 10 min.
GENERAL:
Dimensions:
Height: 175mm (6.9 in)
Width: 395mm (15.6 in)
Depth: 300mm (11.8 in)
Weight: 9 kg (19.8 lbs.)
Maximum Pumping Rate: 30cm3/s (flushing sampling tube) and 5cm3/s (flushing measurement chamber)
Minimum Volume of Air required per

APPLICATIONS

Emissions:

• Exhaust from chemical processes
• Ammonia in stacks
• Measurement of greenhouse gases from agricultural production
• Vent emission
• Scrubber efficiency
• Filter breakthrough
  

Aqueous Monitoring:

• Cooling Tower Waters (VOC's & NH₃)
• Solvent Stripping Processes
• Waste Waters contaminant speciation
  

Automotive:

• Alcohol in vehicle exhaust
• Ammonia and N₂O & NH₃ in diesel exhaust
  

Quality Control:

• Trace impurities in pure gases
• Semiconductor applications
• SF6 leaks from transformers
  

Occupational Health and Safety:

• Hazardous waste sides
• Anaesthetic gases in hospitals
• Ethylene oxide production and sterilization
• Acrylonitrile and styrene in the polymer industry
• Toxic gas releases
  

Indoor Air Quality:

• Tracer Gas Studies
  

MEASUREMENT CYCLE

1. The pump draws air from the sampling point through two air-filters to flush out the "old" air in the measurement system and replace it with a "new" air sample.
2. The "new" air sample is hermetically sealed in the analysis cell by closing the inlet and outlet valves.
3. Light from an infra-red light source is reflected off a mirror, passed through a mechanical chopper, which pulsates it, and then through one of the optical filters in the filter carousel.
4. The light transmitted by the optical filter is selectively absorbed by the gas being monitored, causing the temperature of the gas to increase. Because the light is pulsating, the gas temperature increases and decreases, causing and equivalent increase and decrease in the pressure of the gas (an acoustic signal) in the closed cell.
5. Two microphones mounted in the cell wall measure this acoustic signal, which is directly proportional to the concentration of the monitored gas present in the cell.
6. The filter carousel turns so that light is transmitted through the next optical filter, and the new signal is measured. The number of times this step is repeated is dependent on the number of gases being measured. The response time is down to approx. 13s for 1 gas or water-vapor, or approx. 40s if 5 gases and water vapor are measured.