Element name

Issue

Lessons Learned

Action Required

Reagents and solutions

SYBR dye

Experienced inaccurate

volume of dye

collected by syringe.

Solvent DMSO in

the dye will freeze

below 12˚C.

Consider insulating SYBR

vial or enclosing AMS

modules within an air

conditioned shelter.

Reaction and measuring system

Flow cell

Biocide entering

flow cell.

Need to coordinate with corrosion

engineer for biocide injection time.

Programmed AMS

measurement time

around the estimated

biocide arrival time.

Liquid handling system

Pressure

regulator

Experienced clogging

of pressure regulator

inside AMS.

Select right type of

regulator.

Replaced original needle

type pressure regulator

with a ball valve to reduce

the pressure. Increased

sampling tubing size

from 1/8" to 6 mm.

Pressure

regulator

Experienced damage

of pressure regulator

inside AMS.

Avoid overpressure

of side-stream.

Installed a pressure regulator

on side-stream to reduce the pressure to below 10 bars

before connecting side-stream

to AMS. Installed a restrictor

with a pressure gauge to

monitor inlet pressure.

Corrosion

Experienced corrosion

of fittings.

Delrin fittings is

prone to oxalic

acid corrosion.

Replaced all Delrin fittings

with PEEK fittings.

Leakage

Experienced leakage

and precipitates

around fittings.

Loosening of fittings due to large

temperature

fluctuation.

Equipped all fittings with

lock nut. Tighten fittings,

if necessary.

Electronics and power system

Solar panel

Experienced lots of

dust collection on

solar panels.

Required monthly

cleaning.

Consider installing solar panels at proper height for easy access during monthly maintenance.

Power socket

Power socket is not

water proof.

Risk of water splash

entering power socket.

Replaced power socket with built-in power cable.