View source for Protocol for cleaning of Picarro Vapourizer

Cleaning the Picarro vapourizer cleaning is at times necessary to remove salt residue that builds up from saltwater liquid sample analysis, typically over several weeks. The cleaning procedure takes several hours, and should typically run over night. Preparation and actual cleaning are most conveniently started after lunch, and take 1h for preparation and cooldown, and about 1h for cleaning the vapourizer.

The specific steps are:

# Turn off vapourizer using switch in the back to allow cooldown. Remove power cord from vaporizer.
# '''Important: Leave the Picarro analyzer running, it will control the cleaning software.'''
# Optional: Loan handheld conductivity meter via PT
# Prepare 1.5 l of DI water (from DI generator, not lab standards!) in a large beaker.
# Put beaker with whirlfish on heater plate, at 45-60°C. 
# Place mobile table next to Picarro, get cleaning kit (CF lab shelf under Picarros near door).
# Unmount vapourizer from autosampler and place on cleaning stand. Connect vapourizer serial cable to Picarro using extension serial cable.
# Stabilize vapourizer in vertical position, with stand for funnel above vapourizer inlet and attach tubing as described in Picarro vapourizer cleaning manual (attached below)
# Follow cleaning instructions in Picarro vapourizer cleaning manual
# Overall washing takes 1h. Measure conductivity in DI and first and last washing liquid. Previous results from measuring using different conductivity metres:

<pre style="background-color: Gainsboro">
  DI  1 uS 29 uS
  first cleaning 48 uS 150 uS
  second cleaning 5 uS ?
  last cleaning 1 uS ?
  a) Handheld GEO, b) Handheld GFI (Thermo)
</pre>

# Reattach the vapourizer to its regular place in the Picarro. Typical humidity at start of cleaning software is 40'000 ppmv.
# Start cleaning software to run overnight. The vapourizer cleaner software runs a cycle throughout the night where following valve patterns are applied (x indicates closed, o indicates open):

<pre style="background-color: Gainsboro">
  V1 x x o o x
  V2 x o x x x
  V3 o x x o x
</pre>

At the end of the cleaning sequence, humidty goes to 2-5 ppmv. Normally the software should finish by itself, but it may be ok to terminate it when acceptable humidity levels have been reached (below 10 ppmv).

The PDF document with the Picarro vapourizer cleaning manual is available here:

[[:File:Vaporizer_Cleaning_Procedure_02-17-10.pdf]]