Phymetrix PPMa User manual

PhyMetrix Portable Moisture analyzer
User's Manual for Models PPMa and PPBa

Please visit our website at www.phymetrix.com for other products that may be applicable to your
needs.
Every effort has been made to ensure accuracy in the contents of this manual. Should there be
any doubts to the accuracy of the content please contact the manufacturer.
The contents of this manual are subject to change without notice.
The instructions, procedures, drawings, specifications and concepts contained in this manual are
the property of Phymetrix Inc., and shall not be used as the basis for the manufacture or sale of
apparatus or services, or reproduced or copied or transmitted in any form or by any means
without written permission.
Read this manual before using the analyzer. For personal and system safety, and for
optimum product performance, make sure you thoroughly understand the contents
before installing, using, or maintaining this analyzer.

Warranty
This instrument is warranted, to the original end-user purchaser, against defects in materials and
workmanship. Liability under this warranty is limited to restoring the instrument to normal
operation or replacing the analyzer, at the sole discretion of the manufacturer. Batteries are
specifically excluded from any liability. This warranty is effective from the date of delivery to
the original purchaser. If Phymetrix determines that the equipment was defective, the warranty
period is:
• one year from delivery for electronic or mechanical failures
• one year from delivery for sensor shelf life
If Phymetrix determines that the equipment was damaged by misuse, improper installation, the
use of unauthorized replacement parts, or operating conditions outside the guidelines specified,
the repairs are not covered under this warranty.
Normal wear and tear, parts damaged by abuse, misuse, negligence or accidents are specifically
excluded from the warranty.
Purchaser acknowledges that in accepting and using this analyzer, notwithstanding any contrary
term or provision in the purchaser's purchase order or otherwise, the only warranty extended by
Phymetrix is the express warranty contained herein. Purchaser further acknowledges that there
are no other warranties expressed or implied, including without limitation, the warranty of
merchantability or fitness for a particular purpose; that there are no warranties which extend
beyond the description of the face hereof; that no oral warranties, representations, or guarantees
of any kind have been made by Phymetrix, its distributors or the agents of either of them, that in
any way alter the terms of this warranty; that Phymetrix and its distributors shall in no event be
liable for any consequential or incidental damages, including but not limited to injury to the
person or property of the purchaser or others, and from other losses or expenses incurred by the
purchaser arising from the use, operation, storage or maintenance of the product covered by the
warranty; that Phymetrix’s liability under this warranty is restricted to repair or replacement of
defective parts at Phymetrix sole option; and that Phymetrix neither assumes nor authorizes any
other person to assume for it any other warranty. The warranty shall be void if serial numbers
affixed to the products are removed, obliterated or defaced.

Return Policy / Procedures
If equipment malfunction is suspected or it is determined that the analyzer needs recalibration,
please contact Phymetrix.
Communicate the instrument model number, serial number, application including dewpoint
range being measured, and the details of the problem.
If the analyzer needs factory service you will be issued a RMA and shipping instructions.
The factory will diagnose the equipment and upon determining the problem will notify you
whether the terms of the warranty cover the required repair. If the costs are not covered you will
need to approve the estimated cost in order to proceed with the repair.

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Table Of Contents
1Introduction............................................................................................................................. 1
2Important Principles of Operation .......................................................................................... 2
2.1 Sensor Operating Principle............................................................................................... 2
2.2 Sampling Mechanism Operating Principle ...................................................................... 2
3Precautions ................................................................................................................ 2
4Moisture System Considerations ............................................................................................ 3
4.1 Integrity of the Materials of the User’s System ............................................................... 3
4.2 Moisture Backflow Along the Walls of the Exhaust Tubing........................................... 4
4.3 Temperature Dependant Equilibrium............................................................................... 4
5Sampling Techniques.............................................................................................................. 4
5.1 Choosing a Measurement Site.......................................................................................... 4
5.2 Sample Conditioning........................................................................................................ 5
5.3 Tubing and Fittings .......................................................................................................... 5
5.4 Sample Pressure ............................................................................................................... 5
5.5 Measuring Gasses at Pressures above 50 psia.................................................................. 6
5.5.1 Model PPMa ............................................................................................................. 6
5.5.2 Model PPBa.............................................................................................................. 9
6User Interface Overview....................................................................................................... 10
7Operating the Analyzer......................................................................................................... 10
7.1 Mechanical Connections ................................................................................................ 11
7.2 Sampling and Dry Storing the Sensor............................................................................ 11
7.3 Powering the Analyzer ON or OFF................................................................................ 11
7.4 The Display Mode.......................................................................................................... 12
7.5 Units to Display the Measurement................................................................................. 12
7.6 Pressure Correction........................................................................................................ 13
7.7 Description of “STABLE” indication on the right side of the graph............................. 15
7.8 Navigating Through the Menus...................................................................................... 15
7.9 The Functions Available in the Menus .......................................................................... 17
7.10 External Connections: USB – 4/20mA Analog Out – Battery Use & Charging........ 19
8Data Logging ........................................................................................................................ 20
8.1 Single Data Point Log.................................................................................................... 20
8.2 Continuous Data Logging .............................................................................................. 21
8.3 Retrieving the Data / Clearing the Memory................................................................... 22
8.4 Logging Data Directly into a Personal Computer.......................................................... 22
9Single Point Calibration........................................................................................................ 22
10 Troubleshooting and Maintenance........................................................................................ 22
10.1 Cleaning...................................................................................................................... 22
10.2 Recharging the Battery............................................................................................... 22
10.3 Self Diagnostics.......................................................................................................... 23
10.4 Suspected Erroneous Measurements.......................................................................... 24
11 Specifications........................................................................................................................ 26
11.1 Specifications for Model PPMa.................................................................................. 26
11.2 Specifications for Model PPBa................................................................................... 26
11.3 ATEX Certification - Intrinsically Safe for use in Explosive Atmospheres .............. 27
Appendix A Mini-Demister..................................................................................................... 28
Appendix B Vacuum Pump Option on Model: PPBa ............................................................. 30
Appendix C Analyzer Calibration Log.................................................................................... 34
Revision #3.2 2020

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Revision #3.2 2020

1Introduction
Thank you for purchasing the state-of-the-art Phymetrix Portable Moisture Analyzer models:
PPMa or PPBa. Model PPMa is a weatherproof handheld analyzer, while model PPBa is a
benchtop portable analyzer which includes a built-in metering valve and flow meter; otherwise
both analyzers operate the same. This User’s Manual describes the functions of both of these
analyzers as well as their operating methods and handling precautions. The minor differences
between the two models are addressed as necessary within the document. There are also some
sections that review general knowledge and concepts of water vapor science. Read this manual
thoroughly before using the analyzer. There is also a Quick Setup Manual describing the main
functions and basic procedures for performing measuring operations. Check our website
“www.phymetrix.com” for latest versions of documentation regarding these analyzers.
Conventions used in this manual:
•When using the word “system” in this manual we are referring to the user’s system in which
the moisture content is being measured. This could be a simple configuration of a pressurized
gas bottle with a pressure regulator, or a complex system of dryers, filters, regulators, long
tubing, valves etc.
•When referring to text that is displayed on the analyzer screen, it is presented in this manual
using a font that makes it stand out.
The analyzer part number is located on the front label and also displayed upon power-up and in
the About screen, the dash numbers following the main part number signify options as follows:
–Ifor intrinsically safe certification, the analyzer will be appropriately labeled
PPMa:Ex ib IIC T4 or PPBa:Ex ib IIA T4 (refer to section 11.3 for details)
-Pfor internal pressure sensor, -Afor analog output 4/20mA,
-Vfor vacuum pump option (available with model PPBa only, without “-I”).
Check to see that your analyzer has arrived intact with all accessories. The international plug kit
is supplied only when shipped outside the USA. The rechargeable batteries are factory installed,
and are not user serviceable.
Model: PPMa with accessories Model: PPBa with accessories
Save the packing materials until you have verified that there is no concealed damage, it may also
be useful for future transportation.
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2Important Principles of Operation
2.1 Sensor Operating Principle
The nanopore sensor utilized in this analyzer measures the amount of water vapor molecules that
have entered its pores. This amount is directly proportional to the partial water vapor pressure in
the gas surrounding the sensor, and the partial water vapor pressure is dependant on the water
vapor content of the gas and the total pressure of the gas. Thus to compute the water vapor
content of the gas under measurement the analyzer has to “know” the total pressure of the gas. If
the analyzer was purchased with the pressure sensor option then the total pressure is measured
and utilized by the analyzer, if there is no built-in pressure sensor then the user should enter the
total pressure into the analyzer, this can be easily done by entering atmospheric pressure (the
analyzer default setting) and measuring at atmospheric pressure by allowing the outlet (exhaust)
port to vent without restrictions.
2.2 Sampling Mechanism Operating Principle
The analyzer is equipped with a built-in sampling system which has the required tight seals to
measure low moisture content while also allowing the sensor to move seamlessly between the
desiccant chamber and the sampling chamber. The gas under measurement is exposed only to the
stainless steel walls and Teflon seals of the sampling system. When not being used, with a simple
push of the actuator knob the sensor can be stored in the desiccant chamber and kept at moisture
levels well below 1 part per million.
This method of performing spot measurements by a portable analyzer allows the user to perform
the next measurement from conditions where the sensor will most likely be getting wetter from
its previous state, or does not have to dry down very much. Thus facilitating a fast measurement
by eliminating the requirement for lengthy sensor dry down.
3Precautions
•Observe the appropriate electrical safety codes and regulations. Consult with National
Electrical Code, and/or other nationally or locally recognized procedures relevant to your
location.
•When measuring flammable, explosive or toxic gasses; vent the sample outlet to a safe
and appropriate location.
•When measuring high pressure samples (do not exceed 150 psia or optional 500 psia); be
sure that the system is depressurized before connecting or disconnecting the sample
tubing.
•When connecting gas with pressure greater than 50 psia to the PPMa while the sensor is
in desiccant store, make sure that the pressure is applied gradually (refer to section 5.5).
Hold on to the actuator while purging, as not to allow it to rapidly move out and hit its
internal stop and cause damage to the instrument.
•Corrosives such as Ammonia, HCl and Chlorine should be avoided; H2S and SO2can be
present if the moisture content is below 10 PPMv.
•Avoid extreme temperatures, pressures and mechanical vibration, refer to specifications.
•Do not disassemble the analyzer.
•Do not force the actuator knob; there is only approximately ¾” of travel.
•Do not use with contaminants and liquids, refer to section 5.2 for sample conditioning.
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•Avoid exposing the sensor to ambient air as it may slowdown your next measurement.
•The handheld analyzer Model PPMa is weatherproof and can be left in the rain, however
the inlet and outlet ports must be protected from ingress; this is normally accomplished
by the interconnecting tubing. Do not leave the analyzer exposed to rain or other
contamination sources while the inlet or outlet ports are unprotected. When performing a
measurement at atmospheric pressure, the outlet port is sufficiently protected from rain
by the provided exhaust pigtail if there is at least 1 LPM (2 SCFH) of flow. Be sure to
have the USB connector protective cap secured in order to meet the weatherproof
specifications. The Model PPBa is not weatherproof and can not be left out in the rain.
4Moisture System Considerations
This section is offered as background information. There are several considerations in keeping
your system at a stable and pure moisture level, free of contamination from ambient air moisture:
•The integrity of the materials isolating the pure gas from the external air, including leaks
from poorly secured fittings.
•The backflow of moisture through the exhaust outlet, the exhausts of both the analyzer
and the user system under measurement should be considered.
•The effects of temperature on the equilibrium of moisture and the surrounding materials,
often observed as diurnal cycles in the measurement.
4.1 Integrity of the Materials of the User’s System
Before considering the materials of a system where a specified dewpoint level must be
maintained, one should review two concepts.
•Compared to the structure of solids the water molecule is much smaller. This is true
compared to even the crystalline structure of metals but especially important in the
polymer structure of plastics.
•Water vapor pressure in gasses obeys Dalton’s law of partial pressures, which states that
the overall pressure of a gas is the sum of its constituent gases. And each gas seeks to
equilibrate its pressure across gradients of only its own gas pressure.
Let’s consider air in a pipe at a total pressure of 100 psia, which has been dried down to -40°C
dewpoint. The partial water vapor pressure in the pipe is 0.13mB. If the ambient temperature is
22°C with relative humidity of 30%, then the partial water vapor pressure in the surrounding
atmosphere is 7.9mB or approximately 60 times greater than the partial water vapor pressure in
the pipe. Thus even though the total pressure in the pipe is much greater that the pressure outside,
the reverse is true for the water vapor pressure, and as we discussed earlier the water vapor seeks
to equilibrate its pressure thus it “wants” to flow from the outside to the inside and will do so
through the cracks in the joints (such as poorly tightened fittings, or NPT threads even if they are
properly taped), as well as through the walls of pipes tubes and other vessels. The integrity of the
system is extremely important in maintaining a stable low dewpoint; for dewpoints below -60°C
always use stainless steel or PTFE, while for higher dewpoints you can use copper or galvanized
steel; but never use rubber, Tygon, Nylon or other plastic or tubing. Pressure regulators often use
rubber diaphragms, check and if necessary replace with a stainless steel diaphragm regulator.
Filter bowls should be stainless steel or glass, plastic bowls should be avoided. If a flow meter is
placed at the inlet of the analyzer it should have a glass tube and be rated for the expected
pressure levels, however in general it is best to place flow meters at the analyzer exhaust.
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