Super Systems Simple Dew User Manual

SIMPLE DEW

DIGITAL DEW POINT

ANALYZER

OPERATIONS MANUAL

Super Systems Inc.

www.supersystems.com

7205 Edington Drive

Cincinnati, OH 45249

513-772-0060

Fax: [phone]

Simple Dew Digital Dew Point Analyzer Operations Manual

Super Systems Inc.

Page 2 of 18

Super Systems Inc.

Super Systems Europe

Super Systems México

Super Systems China

USA Office

Corporate Headquarters

7205 Edington Drive

Cincinnati, OH 45249

Phone: [phone]

http://www.supersystems.com

Sistemas Superiores Integrales S de RL de CV

Calle 3 Int.: 11.

Zona Ind. Benito Juarez

Querétaro, Qro. Méx.

C.P.: 76120

Phone: [phone]

http://www.supersystems.com.mx

Units 3 & 4, 17 Reddicap Trading Estate,

Sutton Coldfield, West Midlands

B75 7BU

UNITED KINGDOM

Phone: [phone]

http://www.supersystemseurope.com

No. 335 XianXia Road

Room 308

Shanghai, CHINA

200336

Phone: [phone]

http://www.supersystems.com

Simple Dew Digital Dew Point Analyzer Operations Manual

Super Systems Inc.

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Table of Contents

Introduction ..................................................................................................................................... 4

Specifications .................................................................................................................................. 4

Warnings ......................................................................................................................................... 4

Startup ............................................................................................................................................ 4

Operation ......................................................................................................................................... 5

Instrument Damage ........................................................................................................................ 5

What Is Dew Point? ......................................................................................................................... 6

How It Works ................................................................................................................................... 6

Maintenance/Safety Issues ............................................................................................................. 7

Factory Calibration.......................................................................................................................... 7

Field Calibration .............................................................................................................................. 7

Replacement Parts ........................................................................................................................11

Returning the Unit to SSi ...............................................................................................................11

Warranty.........................................................................................................................................13

Revision History .............................................................................................................................14

Appendix A: Determining the Sensor Temperature in °F ..............................................................15

Appendix B: Determining the Sensor Temperature in °C .............................................................16

Appendix C: Determining the Dew Point in °F ...............................................................................17

Appendix D: Determining the Dew Point in °C ...............................................................................18

Simple Dew Digital Dew Point Analyzer Operations Manual

Super Systems Inc.

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Introduction

Specifications

Warnings

Startup

Thank you for selecting Super Systems Inc. and the Simple Dew as your source for accurate
dew point measurements. The Simple Dew unit is a digital dew point analyzer for standard
range (greater than 0°F or -18°C) measurement. Typical uses of the Simple Dew include
measurement of endothermic atmospheres (with endothermic generators) and
nitrogen/methanol atmospheres, as well as use with plant air systems.

Carefully unpack the Simple Dew - Dew Point Analyzer. If there are any signs of shipping
damage, notify SSi and the shipper immediately.

Measurement Range: 0 to +80°F (-18 to +27°C)
Temperature Range: 0 to +120°F (-18 to +49°C)
Power Supply: 115 to 230 VAC (universal input)—for Part No. 13134
24VDC input—for Part No. 13136
Retransmission Output: 0-1 Volt (range is –50 to +80°F)
Size (Closed Case): 15.25” x 9” x 6.25” (approximately)
Weight: 8.2 lbs (3.7 kg)

Although it is intended for use in an industrial environment, the Simple Dew is a sensitive piece
of analysis equipment. Care should be taken not to drop the analyzer or to operate it in a
manner inconsistent with its intended use.

• Open all sample ports and remove all soot and/or moisture from the lines prior to attaching
the sample tubing for the first time.

• The analyzer should be stored at ambient temperature (65-80°F or 18-27°C) for at least two
hours prior to operation.

• If the unit is to be returned to SSi for service or any other reason, protect the instrument
with at least four inches of foam or other impact-absorbing material on all sides and place it
in an appropriately sized cardboard box.

• This unit is not designed to measure the dew points in corrosive gases, such as Ammonia,

, Chlorine, and HCL.

S0

3

• Please read and understand this Product Manual before operating the unit.

Failure to comply with these conditions may cause damage to the unit that will not be covered
under the warranty. Super Systems Inc. is not responsible for damage to this unit caused by
disregard of these warnings, neglect, or misuse.

The Simple Dew unit was calibrated before it was shipped from Super Systems Inc. You can
begin typical operation as soon as the unit has been allowed to stabilize in a temperature
similar to the temperature in the heat treating department. This stabilization is particularly
important for units that may have been sitting overnight in a delivery vehicle in freezing

Simple Dew Digital Dew Point Analyzer Operations Manual

Super Systems Inc.

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Operation

.
NOTE: Allow the sample port to blow out any soot and / or water before connecting the sample
tube

Instrument Damage

weather. Rapid temperature change can cause condensation on the sensor which will cause the
unit to temporarily display inaccurate readings.

The use of the Simple Dew is somewhat dependent upon the application. For connection to an
endothermic generator, no pump is required since the sample gas is under positive pressure. If
this instrument is to be used on a furnace or other non-positive pressure application, an
external sample pump will be required to deliver the gas to the sensor.

Be sure that the filter (mounted to the bottom of the instrument) is clean and functional, since
high accumulations of soot can hold moisture and influence the dew point measurement. It will
also prevent soot and other contaminants from entering the unit and damaging the sensor.
The optimum flow rate of the sample gas should be between 1.5 and 2.0 Standard Cubic Feet
per Hour (SCFH), although a flow rate as low as 1.0 SCFH is acceptable. If the unit is reading
less than 1.0 SCFH, verify that there are no obstructions to the flow such as a clogged sample
line or filter, or a poorly adjusted knob on the Simple Dew’s flow meter.

Heat Treat Furnace Sampling:

external pump. The sample tube from which the sample is taken out of the furnace should
extend into the furnace past the HOT face of the refractory. For accurate results, a designated
sample port should be used to extract the sample. SSi offers two versions of sample port
assemblies (part numbers 20263 and 20264) which are ideal for this purpose. If a designated
sample port is not available, then a clean “burn-off” port on a Gold Probe, an industry leading
oxygen sensor for atmosphere control, can be used. Readings taken from the burn-off port on a
probe may be artificially high due to the presence of soot in the probe sheath.

Endothermic Generator Sampling:

small restriction valve on the flow meter. A flow rate between 1.5 and 2.0 SCFH is ideal. The
sample should be taken from the endothermic gas manifold after the gas has been cooled

. Failure to do so will result in inaccurate readings and expose the sensor to potential

damage.

The main causes of damage to the Simple Dew are the ingestion of soot and the ingestion of
water. Both of these contaminants will cause erroneous readings in the short term, and cause
long-term damage to the sensor and internal components.

A gas sample must be extracted from the process using an

For applications under pressure, the flow is controlled by the

Soot / Particulate Contaminants

When taking a sample from a furnace or a generator, care should be taken to reduce the
amount of soot that enters the instrument. The filter will trap these particles, but cleaning the
sample line before attaching the Simple Dew will increase the life of the filter. Furnace ports
can be burned off by pumping air through them while hot, or by removing them from the heat
and mechanically cleaning them. Generator ports should be opened before the instrument is
attached to allow any particulate buildup to be blown out. It is also helpful to tap on the port
while it is being blown out to eject any loose particles before the instrument is attached.

If soot is allowed to collect on the dew point sensor in the instrument, it could result in higher
readings. This soot will also retain moisture than can corrode the sensor over time. The sensor

Simple Dew Digital Dew Point Analyzer Operations Manual

Super Systems Inc.

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What Is Dew Point?

How It Works

tip can be cleaned by carefully removing it from the sample block (see Section 2.0 of the Field
Calibration instructions) and rinsing it in isopropyl alcohol. The power should be off while this is
done, and the power should remain off for at least 30 minutes after this procedure to allow all of
the alcohol to completely evaporate.

Water / Moisture Contamination

When a furnace or generator is being started up or cooled down, the resulting gases will
contain unusually high amounts of CO

. When these gases cool, moisture will precipitate out

2

and become condensation inside the sample tubing assembly. Even if the furnace or generator
is operating normally, residual moisture may still be present in the sample tube or plumbing
system. In the same way that the ports are checked for soot (see above) they should be checked
for moisture before attaching the instrument. This is especially important when taking a
sample from a generator, since the sample port is usually preceded by a significant amount of
plumbing. All traces of moisture should be eliminated before attaching the instrument. Failure
to do so will result in erroneous measurements and could result in damage to the analyzer.

The first signs of moisture in the instrument will be visible condensation collecting in the bowl
filter and an unusually high dew point. The upper range of the sensor is +80°F, so if that value
is displayed on the instrument it is probably due to the presence of moisture. If this moisture is
not removed, it will cause the sensor tip to corrode and will eventually require the sensor to be
replaced.

To remove moisture from the instrument, the filter should be removed from the instrument
(since it will probably be wet) and an inert gas such as Nitrogen or Argon should then be flowed
through the instrument for as much time as it takes to dry out. This dry-out time will depend on
the amount of moisture present in the instrument. The condition of the sensor can be
monitored by periodically reading the dew point from the display and watching the value
decrease over time. 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 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, Nitrogen or Argon can be used to
purge the instrument after use.

Dew point can be defined as the temperature at which the water vapor pressure of the gas
equals the saturated water vapor pressure. In other words, it is the temperature at which
condensation will just begin to occur as the gas is cooled. Dew point and relative humidity are
not the same measurement. Relative humidity is the amount of water vapor in the air compared
to the amount the air could hold if it was totally saturated, and it is expressed as a percentage,
not a temperature. To determine dew point, two main variables are required: Relative Humidity
and Temperature. The Simple Dew measures both variables to compute the dew point.