CKD HD-0.5, Instruction Manual, Page: 22 / 23

18
The moisture indicator shows Light green or Pink when the desiccant is aged or when
the heatless air dryer is not operating normally.In such case, refer to item
4,
”
TROUBLESHOOTING
”
on page 6.
14-1.If the desiccant is found to be aged,replace according to item 13,
”
LIST OF
SPARE PARTS
”
on page 15.
14-2.How to read：
The green silica gel,contained in a transparent container,turns to light green
when the relative humidity exceeds 20％. When moisture is absorbed much, it's
changing into orange via pink. When it'll be less than 20 %, it discolors more
greenly than light green.
The outlet atmospheric dew points when the silica gel changes from green to
light green are shown in the next Table.
Outlet air temperature (℃) 10 20 30 40 50
Outlet atmospheric dew point (℃) -12 -4 +5 +13 +21
Dew point can be measured either by using dry ice and thermometer,or through
an instrument using electricity or battery.
In general dry ice is used for measuring dew points up to
–
40℃,while dew points
below
–
40 are measured by means of an instrument.
Here,due attention shall be paid to the tube for taking out the sample air.
Dew point cannot be measured correctly by taking the sample air in vinyl or
nylon tubes since moisture in atmospheric air intrudes into these tubes
because of their water absorbing property.The vinyl or nylon tubes make hardly
any difference in measuring the dew points up to
–
20℃.However,for dew points
below
–
40℃,the measured value becomes 5〜10℃ higher than the actual dew
point.
Furthermore,the measured value does not go down,however long the time may
elapse.
Hence,it is necessary to use teflon tubes,copper tubes,stainless steel
tubes,etc.for taking out the sample air.
１４．HOW TO READ THE MOISTURE INDICATOR
１５．HOW TO MEASURE THE DEW POINT