Drying out the Simple Dew analyzer:

 

Option 1: 

The easiest way to remove moisture is to flow dry compressed air*, nitrogen, or argon through the analyzer, until the dew point reading drops and stabilizes.  This can take up to two days depending on the amount of moisture in the sampling lines and analyzer. 

 

*Dry compressed air is compressed air produced by a facility air compressor that has flowed through a desiccant or refrigerated air dryer with a dew point of 40°F (4°C) or less.

 

Disassemble the sampling line filter to determine if the element is saturated with moisture.  Replace the element if it contains moisture, as leaving it in the sampling line will increase the drying time significantly. 

 

                       

Figure 5

 

Connect a dry gas source to the sampling line of the Simple Dew.  Verify that the pressure is low (less than 2 psi) to prevent damage to the dew point sensor.  Adjust flow through the Simple Dew to 3 to 5 scfh of flow indicated by the flow meter on the front of the Simple Dew.  Allow gas to flow through the Simple Dew and monitor the dew point reading from the sensor.  As the sample line and sensor dry out, the dew point reading should drop and stabilize.

 

 

Option 2:

Moisture can be removed from the sampling line much more quickly if the lines are disconnected and blown out with dry compressed air, nitrogen, or argon.  To remove moisture with this method, follow the steps below:

 

Isolate the sampling line from the atmosphere gas source to the Simple Dew sample line inlet at the filter by disconnecting it on both ends.  Higher pressures can be used for this process as long as the lines have been disconnected at both ends and no sensing equipment is exposed to the high pressure gas.  Blow gas through the sampling line for as long as it takes to remove any visible moisture from the line.  Reconnect the line at both ends. 

 

Figure 6

 

Open the filter housing and wipe out the bowl removing any mosture.  Assess the filter element and replace it if there is any sign of moisture present in that element.  Reassemble the filter.

 

Disconnect the tubing at the filter outlet.  Open the front door of the Simple Dew and disconnect the tubing to the bottom of the Sensor Sampling Block.  Blow gas through the sampling line for as long as it takes to remove any visible moisture from the line.  Reconnect the tubing at both ends.

 

Figure 7

 

Remove the dew point element from its housing by loosening the compression nut.  Visually inspect the element for any signs of moisture.  If there is any moisture on the element, low pressure gas must be flowed past the element, until the element is dry.  DO NOT ATTEMPT TO REMOVE THE MOISTURE FROM THE ELEMENT WITH A CLOTH OR COMPRESSED AIR AS THIS CAN PERMANENTLY DAMAGE THE ELEMENT.  With the element out of its housing, disconnect the tubing on both ends and blow gas through the housing, until all of the moisture has been removed.  A dry cloth or paper towel can also be used to remove moisture from inside the housing.  Reconnect the tubing and reinstall the dew point element.

 

 

Figure 8

 

Remove the tubing at both ends between the dew point element housing and the bottom of the flow meter.  Blow out the tubing to remove the moisture.  Reconnect the tubing.

 

                                      

Figure 9

 

Visually inspect the flow meter for signs of moisture in the flow tube where the black float is located.  If necessary, blow dry gas through the flow meter, until all of the moisture is removed.  Reconnect the tubing.

 

Disconnect the tubing between the flow meter and sample gas outlet at the top of the Simple Dew housing.  Blow out the tubing with dry gas, until all of the moisture is removed.  Reconnect the tubing.

 

 

Figure 10

 

To test if it is operating properly, verify the ambient dew point against a web-based weather station that will report the ambient dew point for your area.  If the displayed reading is within three degrees (3°) of the reported dew point when the instrument is taken outside, then all of the moisture has probably been successfully removed.  The wet filter and sample tubing can be re-attached after they have been completely dried out.  The filter element will regain all of its original filtering properties after it has dried out.

 

To prevent the possibility of moisture damaging the instrument, be sure that the measured dew point is below ambient levels before it is stored.  If necessary, dry compressed air, nitrogen, or argon can be used to purge the instrument after use.