AppliTek NV

Online monitoring solutions for determination of moisture in dry chlorine - Monitoring and Testing

The purpose of determination of moisture in dry chlorine is threefold: prevent corrosion, prevent formation of ferric chloride and control the overall drying process. AppliTek offers two different solutions for determination of moisture: one traditional method by means of an amperometric phosphoric pentoxide (P2O5) electrochemical cell, or a more advanced technique based on tunable diode laser technology (TLDS). Both analyzer systems are installed in a compact protective corrosion resistant cabinet.


Wet chlorine (typically > 12mg/l H2O) is corrosive for a lot of materials used in the further chlorine processing after the dryers. For this reason chlorine is dried to prevent corrosion. Process dryers with limited drying capacity perform this drying process and multiple dryers are used to allow regeneration in case of saturation. The chlorine drying process needs to be controlled by an on-line measurement of moisture in chlorine gas.

Parameters: Moisture

  • Determination of moisture by traditional amperometric P2O5 cell or by advanced TLDS

Typical measuring ranges  
0 – 10 ppm vol  / 0 – 20 ppm vol  / 0 – 50 ppm vol  / 0 – 100 ppm vol / 0 – 200 ppm vol  H2O
TLDS: 0 – 50 ppm vol H2O

Analysis method  
Amperometric P2O5 electrochemical cell
Or tunable diode laser spectroscopy (TLDS)

Detection limit    

Response time
1min.  increasing from 2 to 100 mg/m³ (T50)
3 min. declining from 100 to 2 mg/m³ (T50)

Better than ± 5 % full scale range