Teledyne hfc-303-307 ユーザーズマニュアル

 

 

 

 

The end cap on the inlet side must be removed to gain access to shunt assembly.  First remove power 

and shut off the supply of gas to the instrument.  Disconnect the fittings on the inlet and outlet sides of 
the transducer and remove it from the system plumbing.  On both the HFM-301 and HFC-303, remove the 

four Allen head screws holding the end cap to the instrument.  Carefully remove the “O”-ring sealed end 
cap and shunt, noting their order and the proper annular orientation of the shunt.  The shunt position is 

critical to the flow dynamics and can substantially affect the instrument linearity.  The shunt can be 
severely damaged if dropped.  Examine the shunt.  If damaged, dirty or blocked, clean and replace as 
applicable.  Reassemble in the reverse order of disassembly.  Secure the endcap with 65 in lb. (7.3 N.m) 

to 85 in lb (9.6 N-m) of torque on each high-tensile socket head cap screw.  Use of a fastener other than 
the one mentioned here may result in leakage at the seal.  Recalibration of the 301/303 series 

For the HFM-305/307 remove the four 12 point bolts securing the endcap while carefully holding the 

endcap in place. Carefully remove the metal gasket sealed endcap and shunt, noting their order and the 
proper annular orientation of the shunt.  The shunt position is critical to the flow dynamics and can 
substantially affect the instrument linearity.  The shunt can be severely damaged if dropped.  Examine 

the shunt.  If damaged, dirty or blocked, clean and replace as applicable.  Reassemble in the reverse 
order of disassembly replacing the used metal gasket with a new one. Secure the endcap with 35 ft lb. ( 

47.5 N.m) to 40 ft lb. (54.3 N.m) of torque on each 12 pt bolt. Use of a fastener other than the one 
mentioned here may result in leakage at the seal.  Recalibration of the 305/307 series instrument is 

For the HFM-306, remove the six hex socket bolts from the inlet end cap. Remove the end cap and 
ensure that the o-ring is not damaged. Remove the flow conditioning screen assembly and if damaged, 

dirty or blocked, clean and replace as applicable. Carefully remove the flow straightener and shunt 
assembly. If damaged, dirty or blocked, clean and replace as applicable. Reassemble in the reverse order 

of disassembly. Recalibration of the HFM-306 instrument is necessary. 

Zero 

Span 

Control 
Loop Gain 

PC 
Board