Model DPC3500
Continuous Low-Range Dew Point Analyzer
PRODUCT MANUAL
Introduction:
Thank you for selecting Super System’s DPC3500 as your Continuous Low
Range Dew Point Analyzer. Please keep this manual in a secure place for future
reference.
Unpacking
Carefully unpack the unit. The shipment should contain the following
components:
1 Model DPC3500 12” x 10” x 6” Enclosure
1 Low Range Dew Point Sensor
20’ Sensor Wire
1 Remote Mounting Assembly
1 Product Manual
If any of these components are missing or damaged, please contact SSi
immediately at (800) 666-4330.
General Description:
The DPC3500 is designed to detect moisture content in gas samples from -148°F
to +20°F (-100°C to -7°C) dew point. The readings are remotely displayed in
either Fahrenheit or Celsius on the door of the enclosure. In addition to the
visual display, the DPC3500 also provides 4-20mA and RS232 outputs for data
collection.
The DPC3500 is designed to provide continuous readings. Response times are
rapid as long as the sensor remains bathed in a sample gas stream that has a
low dew point. If the sensor is allowed to reach ambient dew point (greater than
40°F or 4°C), it will take a considerable amount of time for it to achieve readings
at the low level. When installed and operated properly, the Remote Mounting
Assembly (supplied by SSi) will allow the sensor to be continuously exposed to a
low-dew atmosphere, which will result in rapid response times.
It is important to note that this analyzer is designed to measure dew point in
gases that are non-corrosive. Some gases that can cause damage or failure to
the sensor are trace amounts of SO
and any other gases that could cause corrosion.
, high concentrations of NH3, Chlorine, HCL,
3
Super Systems, Inc. DPC 3500
Manual # 4551B Page 1 of 5
Model DPC3500
Continuous Low-Range Dew Point Analyzer
PRODUCT MANUAL
Specifications:
Measurement Range -148°F to +20°F (-100°C to -7°C)
Accuracy –75°F to +20°F (–59°C to -7°C) +/- 1.8°F (+/- 1°C)
Accuracy –148°F to –76°F (–100°C to –60°C) +/- 3.6°F (+/- 2°C)
Outputs 4 to 20 mA
Display °F or °C
Sensor Material Metalized Ceramic
Sensor Guard 80µ Sintered Metal Guard
Operating Pressure Vacuum to 5,000 PSIG
Operating Temperature –40°F to +140°F (–40°C to +60°C)
Sample Flow Rate 5-10 SCFH Recommended
Power Requirements 120 VAC, 1 Phase, 60 Hz
Operation:
The DPC 3500’s sensor is manufactured from a ceramic tile that is plated and
vapor-deposited to form a surface that varies its electrical capacitance when
exposed to small changes in water vapor pressure. This information, along with
temperature readings from the tip of the sensor, is used by the microprocessor to
determine dew point.
The dew point of the gas in the sample line is displayed on the front panel. A
switch to the right of the display toggles between showing the readings in
degrees Fahrenheit and degrees Celsius. An indicator light to the right of the
display will indicate the display’s operating mode.
Startup:
The DPC3500 was calibrated before it was shipped from Super Systems, Inc.
After the unit is properly installed (see “Wiring Connections” and “Sample Cell
Installation”), power can be applied immediately. The flow meter on the Remote
Mounting Assembly should be adjusted to provide approximately 5 to 10 SCFH
of sample gas to the sensor. The rate of sample flow does not have any impact
on the measured dew point, but a higher flow rate will result in a faster response
time.
At the time of installation, the sensor will be reading the ambient dew point. It will
take between 3 and 6 hours of immersion in the sample stream for the unit to
thoroughly “dry out” the sensor before it stabilizes at the correct readings. This
delay is only at initial startup when the system is installed for the first time. The
unit is intended to operate with a constant, steady stream of sample gas
continuously bathing the sensor. This will prevent the sensor from absorbing
moisture from ambient air, and will allow for continuous real-time monitoring of
the sample stream.
Super Systems, Inc. DPC 3500
Manual # 4551B Page 2 of 5
Model DPC3500
Continuous Low-Range Dew Point Analyzer
PRODUCT MANUAL
Sample Cell Installation:
The cell must be installed in the Remote Mounting Assembly (SSi Part Number
13123), which is provided with the unit. All of the necessary components for
installing the sensor are included in this kit. Although this installation does allow
for some design flexibility, it is important that only stainless steel tubing and
fittings are used to carry the sample gas to the sensor.
When installing the unit, verify that all fittings are tight,
since any leaks will cause inaccurate readings.
During the operation of this unit, sample gas will constantly
be flowing through the sensor and out of the vent.
Depending upon the type of gas being sampled,
appropriate safety precautions should be taken for proper
venting of the sample gases after they exit the sampling
assembly.
Sample Tubing Materials:
When determining the moisture content of gas samples,
the materials used to transport the gas samples are
extremely important. As the gas passes through tubing,
the polarity of the moisture molecules will cause them to be
attracted to the tubing. Any moisture that remains on the
wall of the vessel does not have the opportunity to travel to
the sensor, so it will reduce the sensor’s response time.
P/N 13123
Remote Mounting Assembly
through the walls of the tubing, even in cases where there is considerable
positive pressure.
Super Systems, Inc. recommends that only stainless steel is used as the tubing
material for measuring low dew points (below -50°F). It is also important to note
that to maintain the integrity of the entire sampling system, all of the necessary
valves and fittings should also be constructed of stainless steel. These material
precautions do not need to be followed “downstream” (after the sensor), since
the moisture content of the gas at this point is unimportant.
Also, some tubing materials (rubber, copper, PVC, etc.) are
porous enough to allow for moisture penetration directly
Calibration:
The calibration of the DPC3500 is traceable to National Institute of Standards
and Technology (NIST) standards. Each sensor has a unique serial number, and
the calibration data can be found on the Certification Sheet located at the back of
this manual. Due to the sensitivity and complexity of the metalized ceramic
moisture sensor, this unit cannot be user calibrated and must be returned to SSi
for recalibration and recertification. It is recommended that the sensor be
recalibrated every twelve months. Each sensor is interchangeable without the
need for display recalibration, so only the sensor needs to be returned for
recalibration, not the entire panel.
Super Systems, Inc. DPC 3500
Manual # 4551B Page 3 of 5
Model DPC3500
Continuous Low-Range Dew Point Analyzer
PRODUCT MANUAL
Wiring Connections:
The power and communications wires for the sensor are connected to a plug that
is attached to the head of the sensor. The wires will already be attached to this
plug at SSi, however for reference the wiring for this plug is:
Sensor Plug Terminal #1: Green Wire (to location #1291 on terminal strip)
Sensor Plug Terminal #2: White Wire (to location #1281 on terminal strip)
Sensor Plug Terminal #3: Red Wire (to location #1261 on terminal strip)
Sensor Plug Terminal #4: Black Wire (to location #1271 on terminal strip)
20 feet of sensor wire is included with the unit, however it is capable of operating
over substantially longer distances if required. When attaching the necessary
wires to the terminal strip inside the panel, all connections should be made
according to the following diagram:
1.0 AMP
1000 Line
1002 Neutral
GND Ground
SPARE N/A
1261 Red
1271 Black
1281 White
1291 Green
1331 Positive
1341 Negative
1361 Common
1371 Receive Data
1381 Transmit Data
COMMUNICATIONS
120V
1 PHASE
60 HZ
UNUSED
FROM SENSOR
CONNECTOR
4-20 mA
OUTPUT
RS 232
Communications:
The 4-20 mA output correlates to a dew point range of –148°F to 32°F (–100°C
to 0°C).
Super Systems, Inc. DPC 3500
Manual # 4551B Page 4 of 5
Model DPC3500
Continuous Low-Range Dew Point Analyzer
PRODUCT MANUAL
Spare Parts:
Description Part Number
Factory Calibration & Re-Certification 13122
Sample Tubing Assembly 13123
Sensor Wire (50’) T.B.D.
Low Dew Point Sensor 31413
+15 VDC Power Supply 31330
Revision History:
Rev. Description Date
- Initial Release 11/26/01
A SSi Address Update, General Update 04/14/05
B Updated flow rate, fuse rating, and other modifications 11/14/06
Super Systems, Inc. DPC 3500
Manual # 4551B Page 5 of 5
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