Teledyne t320u Manuale Utente

Theory of Operation 

Teledyne API – Model T300/T300M CO Analyzer 

  By placing the pump down stream from the sample chamber several problems are 

avoided.   

  First the pumping process heats and compresses the sample air complicating the 

measurement process.   

  Additionally, certain physical parts of the pump itself are made of materials that 

might chemically react with the sample gas.   

  Finally, in certain applications where the concentration of the target gas might be 

high enough to be hazardous, maintaining a negative gas pressure relative to 
ambient means that should a minor leak occur, no sample gas will be pumped into 
the atmosphere surrounding analyzer. 

 

To maintain a constant flow rate of the sample gas through the instrument, the 
T300/T300M uses a special flow control assembly located in the exhaust gas line just 
before the pump.  In instruments with the O

2

 sensor installed, a second flow control 

assembly is located between the O

2

 sensor assembly and the pump.  These assemblies 

consist of: 

  A critical flow orifice. 
  Two o-rings: Located just before and after the critical flow orifice, the o-rings seal the 

gap between the walls of assembly housing and the critical flow orifice. 

  A spring: Applies mechanical force needed to form the seal between the o-rings, the 

critical flow orifice and the assembly housing. 

06864B DCN6314