Teledyne 8800P User Manual

instruction
manual

Model 8800P

TRACE MOISTURE ANALYZER

Teledyne Analytical Instruments
A Business Unit of Teledyne Electronic Technologies

8800P Series Trace Moisture Analyzer Instruction Manual

When calling your representative for technical support, please have your serial numbers available.

Sensor Serial No.: _______________
Instrument Serial No.: _______________

Your Representative is:

Except as may be provided by contract, this document and all specifica­tions and drawings contained are the property of Teledyne Analytical
Instruments, are issued in strict confidence, and shall not be reproduced
or copied or transmitted, in any form or by any means, or used as the basis
for the manufacture or sale of apparatus, programs, or services without
permission.

Copyright © 2000 by Teledyne Analytical Instruments

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1. Introduction

The 8800P is a portable, hand-held, microprocessor controlled, battery operated dew­point meter with built in dry-storage for the sensor. The instrument is ideally suited for all
applications, where quick and precise measurements are required.

Standard Equipment:

1.8800P Portable Instrument with
sensor, desiccant cartridge and
lithium battery.

2. 2 VCO to Swagelok fittings and 2
Swagelok to barbed hose fittings.

3. Calibration bulb.

4. Shoulder strap.

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Optional Equipment:

5. VCO to VCO Fittings.

6. Pig tail.

7. Flexible stainless steel hose.

8. Pressure regulator, all stainless
steel, (preset at 1.5 atm) with
mounting bracket.

9. Coalescing filter, all stainless steel
with mounting bracket.(not shown)

10.Wall transformer (with factory
installed I/O option).

11.Replacement desiccant cartridge.

12.Padded transport case.

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2. Precautions

• Warranty limitation: The 8800P’s sample cell/piston assembly should not be disas­sembled except by factory trained personnel. The warranty is voided, if the sample
cell piston assembly is disassembled by the customer.

• Avoid contaminated sample streams: The 8800P has been designed to allow for fast
and precise measurements of dewpoints as low as -100 °C. Therefore, all surfaces in
contact with the sample stream are made from electropolished stainless steel. This
minimizes the time for the instrument to reach equilibrium with the sample stream,
thus speeding up the measurement. The introduction of corrosive gases or gases
contaminated with oils, solvents etc. may damage or coat the electropolished sur­faces and slow down the measurement. Surfaces contaminated with oils etc. can be
cleaned by factory trained personnel (please contact your sales representative). Sur­faces damaged by corrosive gases are damaged permanently, causing longer
response times. Gases containing chlorine, ammonia, HCl or SO2 may also cause

damage to the sensor. SO2 can be monitored when the moisture content is low.

• Avoid liquid water: Avoid the introduction of liquid water into the sample cell, as this
may damage the sensor. Do not breathe directly into the instruments sample ports,
as condensation may form which could damage the sensor element. If liquid water
can not be av oided, or der the XTR-65W senso r which is w ater proof , b ut has a limit ed
range, and a slower dry down response.

• Avoid high pressure: The 8800P has been designed for operation at pressures
slightly above atmospher i c, however each sample cell/sensor piston/dry-storage
assembly has been tes ted for pressures up to 120 PSI. Do not introduce sample
streams, whi ch could cau se pressure rises ab ov e 100 PSI. Mak e your m easurements
at atmospheric pressures, and use the pressure calculation feature to calculate dew­points at higher pressures. Ask your representative for a regulator installation kit.

• Exercise Caution with Hazardous Gases: Please use appropriate precautions if the
sample you are about to measure is hazardous. Place the unit in a safe area, if it is to
be used with hazardous gases. Please be aware that the possibility of a small leak
always exists. Such a leak will not influence the accuracy of the measurement, but
may represent a risk if the sample gas is of hazardous nature.

• Avoid Extreme temperatures: Do not install the unit near heat sources such as radia­tors or air ducts. The instruments’ operating temperature range is -10°C to 50°C.

• Avoid Mechanical Vibration: Do not install the unit in places subject to extreme
mechanical vibration or shock. Use resilient mounting, if shock and vibration are not
avoidable. Call your representative if in doubt.

• Avoid long exposures of sensor element to room air: For reasons explained later in
this manual (section 7), do not expose the sensor to room ai r for longer then neces­sary (1 - 2 Minutes). The sensor is exposed to room air, when the sensor actuator is
in the out position and no sample line is connected, or the sample gas is shut off. It is
best to push the sensor bac k into d ry-storage , after a measu rement is co mplete d and
whenever the instrument is not in use.

• Do not force the Actuator: Remove any port obstructions (such as shipping caps)
before operating the Actuator.

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3. Principle of Operation

Dewpoint sensors, like all hygroscopic materials, adsorb much faster than they desorb.
Therefore, an accurate measurement will be obtained much faster, if at the beginning of
the measurement, the sensor is at a dewpoint drier than the gas to be measured. The
8800P design allows the sensor to be moved directly between dry-storage and the sample
cell, without any exposure to ambient air.

Sensor in Sensor In

dry-storage position measuring position

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1. Sample Ga s In 7. Sensor Actuator

2. Sample Gas Out 8. Desiccant Chamber

3. Piston 9. Filter Mesh

4. Sample Cell 10.Electronic Board

5. Sensor 11.Instrument Case

6. Spring loaded PTFE seals

1111

The drawing on the left shows the 8800P with the sensor in dry-storage position. The sen­sor is enclosed in a gas-tight container and surrounded by desiccant. The sample gas
passes through the sample chamber and prepares the environment for measurement.
Blocking of the outlet port will pressurize the sample ch amber and move the piston into
the position sho wn on the right. The sensor is no w exposed to the sampl e gas without ev er
having b een exposed to am bient air . Af ter t he measurement is taken, pushing in the sen­sor actuator will return the sensor into dry-storage, where it will dry down and ready itself
for another fast measurement.

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A note about dry-storage
The dry-storage consist of a stainless steel container filled with desiccant. The elec­tropolished st ainless steel sensor guard slides between the dry-storage and the sample
cell through a spring energized PTFE seal, assuring maximum possible gas tightness
and minimum gas transport between the two chambers when the sensor is moved. When
in dry-storage, the sen sor guar d is separ ated from the de siccant b y a stai nless stee l wire
mesh with a thic kness of 127µ (0. 005”) and a me sh size of 100µ . This k eeps the distance
between the sensor and the desiccant to a minimum, which is critical for fast and low dry­downs, while protectin g the sensor from contaminatio n with desiccant par ticles.
The factory supplied desiccant provides dry-storage dewpoints as low as -80°C when
fresh. When the sensor is pushed into dry-storage it will take some time to dry down
completely and reach equilibrium with the dewpoint in the dry-storage. The dry-down
time to equilibrium depends on how wet the sensor was before it was returned to dry­storage, and in case that it was completely wet, how long it had remained in wet condi­tion.
To take full advantage of the dry-storage, make sure, that the dry-storage dewpoint is
below the expected dewpoint of the sample gas by periodically checking the indicated
dewpoint afte r the senso r has remain ed in dry-storag e f or an e x tended period of time , f or
example o ver night. Replace the d esiccant cartridge, if th e dry-storag e de w point is m uch
higher than -80°C and above your expected sample dewpoints.

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4. Operating the 8800P

4.1. Sample Hook-up

4.1.1. Fittings

The 8800P can be hooked up to the sample gas using a variety of fittings, depending on
the application. The instruments’ sample ports are 1/4” VCO female, to assure proper
seals for even the lowest dewpoint measurements.
Depending on the application and needs, we recommend the use of on e of the following
methods of attachment:

•VCO
stainless steel hoses, available optionally.

•VCO
nections are acceptable.

•VCO
above -65°C and should in all cases be used only with PTFE tubing.

4.1.2 Recommended Pipes

Stainless steel pipes should be used exclusively, for dewpoints below -65°C. Your repre­sentative ha s a fle xible s tainless steel ho se av ailab le. The length of the sam ple line to the
instrument should be kept as short as possible, to assure fast equilibrium. We recommend
the attachment of at lea st 12" long stainless stee l pipe at the outlet port to avoid bac k flow
of ambient air when sampling at low flow rates, ask your representative for the optional
pigtail.
PTFE tubes are perfectly acceptable, and offer advantages due to their flexibility, for dew­points above -65°C. However, PTFE tubes should be kept as short as possible.
Under no circumstance s use rubber or plastic tu bes, which are bo th, hygr oscopic and per­meable. No valid measurements can be expected when such materials are used.

VCO: This method is ideal for all applications, including the use of flexible

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Swagelok: This method is suitable for all applications where rigid pipe con-

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Swagelok ➜ Barbed Hose Fitting: This method is acceptable for dewpoints

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4.1.3. Sample conditioning

• Pre-filters: Do not use any pre-filters for oil, particles or liquid water when measuring
dewpoints below -65°C. Pre-filters store and release water vapor, and slow down and
distort the measurement at low dewpoints.

• Pressur e re gulators: Do not use a pressure regulator containing any materials other
than stainless steel, for dewpoints below -65°C. To ensure the use of the right prod­uct, use regulators provided by your sales representative.

4.2. Measuring

• Turn the unit on by pushing the Power button.

• Select the desired engineering units, using the up or down buttons.

• Take note of the indicated dewpoint while the sensor is still in dry-storage.

• Introduce the sample gas into the unit while the output port is unobstructed. Wait one
minute, for ev ery 10°C below 0°C of expected dewpoint, to allow the sample chamber
to adapt to the sample dewpoint.

• Block the outlet po rt. The small pressure build-up in the sample chamber should be
sufficient to push out the piston and move the sensor into the sample chamber. If not
sufficient, assist by gently pulling on the sensor actuator located on the front of the

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