background
blue
br
bromine
check
checking
chemical
chlorine
cl
clarity
cleanness
clear
color
composition
container
exam
experiment
female
finger
glass
hand
hold
holding
level
measure
measuring
monitor
ph
pollution
pool
probe
purity
quality
result
sample
sensor
strip
surface
swimming
test
tester
transparent
trial
try
tube
verification
verify
view
water
woman