Axis AGS200/T250, AGS120/T250 User Manual
User Manual
Moisture Analyser
AGS series
Measuring method description
Ver. 1 2014-08-28
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USER MANUAL
Contents:
1. General description 3
2. Completeness 3
3. Security rules 4
4. Environment protection 5
5. Technical data 5
6. Keys and indicators 6
7. Preparing moisture analyser to work 7
8. Interfaces 9
9. General working rules 9
10. Description of thermogravimetric analysis 10
10.1 Infrared radiation source 10
10.2 Infrared radiation drying description 10
10.3 Drawing and preparation of a sample 11
10.4 Tools requirements 11
10.5 Single-use pans 11
10.6 Placing a sample 11
10.7 Glass fibre filter 12
10.8 Selection of drying parameters to the sample material 12
10.9 Other practical notes 13
11. Moisture analyser functioning description 14
11.1 Switching on 14
11.2 Drier operation modes 15
11.3 Calculation methods 16
11.4 Drier operation parameters setting 17
11.4.1 Drying profiles 18
11.5 Moisture analyser settings storing 19
11.5.1 Saving settings 19
11.5.2 Loading saved settings 20
11.6 Initial moisture analysis 21
11.7 Proper moisture analysis 23
11.8 Internal thermometer indications correction 24
12. Connecting to a computer or a printer 27
13. Testing and calibration of the balance 29
14. Moisture analyser as a balance 31
14.1 Units 31
14.2 Auto-zeroing 32
14.3 Calibration 33
15. Maintenance and repairs of small defects 35
Declaration of Conformity 37
Drying parameters for different substances (examples) 38
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1. General description
AGS series moisture analyser is destined for fast and precise moisture determination.
The moisture analyser is based on two cooperating devices: the balance, used to
measure current sample weight, and the dryer, which dries the sample using halogen
heaters. Drying parameters may be set according to user preferences. See appendix.
Moisture analysers are mainly destined for use in quality control in food industry,
building materials industry, biotechnology, pharmacy, environment protection and
others.
Moisture analysers may be also used as laboratory balances for routine weighing
(without drying).
2. Completeness
Standard package consists of:
1. Moisture analyser,
2. Pan shield, pan support, pan handle,
3. Single-use pans – 10 pcs,
4. Power supply cord,
5. User manual,
6. Guarantee card.
Options on demand:
6. PT-105 control thermometer with GT-105 sk-8 probe (silicon cable, 160°C) or with
GT-105 so-8 probe (cable with steel braid)
7. Distance sleeve 15mm – 1 piece
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3. Security rules
To avoid electrical shock or damage of the moisture
analyzer or connected peripheral devices, it is necessary
to follow the security rules below.
To feed the analyser use only mains socket with ground contact.
Dryer chamber cover heats up to 40°C, but perforated cover at the top may
heat up over 60°C. Do not touch the cover top during drying as it may cause
severe burns!
During heating, the halogen heaters warm up to very high temperature. Avoid
touching the heaters as it may cause severe burns!
All repairs and necessary regulations can be made by authorised personnel
only.
Do not use the analyser when its cover is opened.
Do not use the analyser in explosive conditions.
Do not use the analyser in high humidity.
If the device seems not to operate properly, plug it out of the mains and do not
use it until checked by authorised service.
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4. Environment protection
According to legal regulations it if forbidden to dispose
wasted electronic equipment in waste containers.
Please return wasted device to the point of purchase or other company
specialised in recycling of wasted electronic components.
5. Technical data
Technical data Moisture analyzers
Model AGS200/T250
Range (Max) 200g
Readout unit (d) 1mg
Work temperature +18 + +33°C
Humidity readout precision 0,01%
Humidity results repeatibility
for sam ple 2g … ± 0,3%, for 5g … ±0,06%
Drying maximal temperatura 250°C
Sample time
1 ÷ 180s
Maximal drying time 10h
Halogen radiators 2 x 500W 118mm
Chamber heating time up to 100°C about 1 min.
Pan dimensions
ɸ 90mm
Connections Rs232C (for computer and printer), USB (for computer), PS2 (for computer keyboard)
Dimensions (with legs) 215(235)x345x200mm
Drying chamber dimensions ɸ 108 x 20mm
Supply 110V 60Hz 300VA
Weight 7 kg
Recommended calibration weifht (OIML) F2 200g
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6. Keys and indicators
T = 24,35 C
m = 4,321g
t = 0:00:00s
m0= 0.000g
%
START
SET
RAP
MEM
STOP
T
- tare (subtract package weight from weighed mass)
I/
- switch- on / switch-off (standby),
ENTER
CLR
- confirmation / select the option,
- cancel operation
.
- decimal point,
1/F1
- digit key 1 / START – start measurement (drying),
2/F2
- digit key 2 / SETTINGS – moisture measurement parameters
setting,
3/F3
- digit key 3 / STAT – drying chart, measurement report,
4/F4
- digit key 4 / MEM – settings memory,
5/F5
- digit key 5 / STOP – instant drying termination,
6/0
- digit key 6 / zeroing (optional)
7/
- digit key 7 / printout (data transmission),
8/
- digit key 8 / autocalibration (unused function),
9/MENU
- digit key 9 / enter the function menu
0/
- digit key 0 / mode switching (analyser – balance)
>
- enter the option,
<
- leave the option,
∧
- navigation / move the cursor up,
∨
- navigation / move the cursor down,
indicator
- result stabilisation,
bar indicator
- total load indicator (0-100%),
indicator OFF
- stand-by mode (when switched-off with I/ , key),
Max, Min, d, e
- metrologic parameters.
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7. Preparing moisture analyser to work
During heating, the halogen heaters 1 warm up to very high
temperature. When drying chamber is opened avoid touching the
heaters as it may cause severe burns or damage the heaters!
Dryer chamber cover 3 heats up to 40°C, but perforated cover may
heat up over 60°C. Do not touch the top cover during drying as it may
cause severe burns!
1
2
3
7
6
5
4
1 – halogen heaters
2 – temperature sensor
3 – chamber cover
4 – dryer chamber
5 – pan plate
6 – single-use pan grip
7 – single-use pa
8 – distance stake
9 – regulated legs
10 – level
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1. Take all contents out of a package: the moisture analyser and packed separately: the
tin pan shield, single use pans, the pan handle and the pan support. It is
recommended to keep the original moisture analyzer package in order to transport
the moisture analyzer safely in future
2. Place the moisture analyzer on a stable ground not affected by mechanical vibrations
and airflows.
3. Level the moisture analyzer with rotating legs 9 so that the air bubble in water-level
10 at the back of the moisture analyzer is in the middle and the moisture analyser
rests on all four legs.
4. Open the dryer chamber with the handle at the front. Put the pan shield 4 on three
distance sleeves 8. Gently insert the pan support 5 into the mechanism hole.
5. Place a single use pan 7 on the pan handle 6 and put the pan on the pan support
(the handle shou ld rest on the pan shield so that it does not touch the pan or the pan
support).
6. Close the drying chamber cover 3 and plug the device to the mains (230V).
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USER MANUAL
7. After self-tests and result stabilisation zero indication is displayed. The dryer starts
initial heating (signalised with an appropriate communicate). After initial heating the
moisture analyser is ready to work.
When temperature during initial heating exceeds 105°C or heating
time is longer than 1 minute, terminate initial heating with CLR key and
check if the temperature sensor 2 works properly and if both halogen
heaters light 1 (see chapter 15).
In case any defect occurs contact an authorised service point.
8. The moisture analyzer should not be used to weigh ferromagnetic materials due to
accuracy decrease.
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8. Interfaces
The moisture analyser is equipped with RS232C interface to connect a printer or a
computer and with PS2 port to connect an external computer keyboard.
RS232C
PS2
1
RxD
(receiver)
2
TxD
(transmitter)
3
4
GND
5
7
8
case
+5V
6
5
4 3
2 1
Data
Clock
GND
9. General working rules
During transportation remove the pan, the pan support and the pan
shield and place it in a separate package.
1. Distribute a sample all over the pan. A sample surface should not touch temperature
sensor placed above the pan.
2. The balance is equipped with the tare equal to its range. To tare the balance press
T key. Writing the tare does not extend measuring range, but only subtracts the
tare value from a load placed on the pan. To make weight control easier and to avoid
range overdrawing, the balance is equipped with weight indicator (graduated in
percentages).
3. Do not overload the moisture analyzer more then 20% of maximum load (Max).
4. The mechanism of the balance is a precise device sensitive to mechanical strokes
and shocks. Do not press the pan with a hand.
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10. Description of thermogravimetric analysis
This section gives some practical details about moisture analysis using infrared
radiation for reliable results and easier use of moisture analyser. The description is
based on a pre-production experience and
customers‟
suggestions.
Moisture in substances is an essential quality factor of technical and economical
importance.
Methods of determining moisture may be grouped in two main categories: absolute and
deductive.
Absolute methods are based on simple relations, e.g. weight decline during drying.
Thermogravimetric analysis used in AXIS moisture analyser is an example of this
method.
Deductive (indirect) methods measure physical quantity related with moisture, e.g.
electromagnetic waves absorption, electrical conductance, acoustic wave speed. Some
of these methods, unlike thermogravimetric analysis, enable to determine water content.
Thermogravimetry - lat. thermo – heat, gravi – weight, metry – method
Thermogravimetric analysis – a process of determination of a substance mass
decline as a result of heat-up. The sample is weighed before and after heating-up, the
difference is calculated in relation to initial weight or final weight (dry mass).
Moisture in substances
Thermogravimetric analysis includes all ingredients evaporating from substances during
heating-up, which results in weight decrease.
In result of the above, determining of moisture content in substances is not equal water
content. Beside water, moisture consists of all other volatile matter: fats, alcohol,
aromas, organic dissolvent and other substances resultant as en effect of thermal
decomposition.
Thermogravimetric analysis does not distinguish water from other volatile matters.
Infrared radiation drying is more effective than traditional methods (e.g. in an oven) as
the radiation deeply penetrates the substance, which shortens drying time.
10.1 Infrared radiation source
ADS series moisture analyser uses 2 halogen heaters (rated power 200W, l=118mm) in
serial connection as a radiation source. The heaters emit also visible radiation, which
does not affect drying process.
10.2 Infrared radiation drying description
Sample drying is a result of absorption of infrared radiation, which results in sample
temperature increase and evaporation of volatile matters.
Infrared radiation penetrates surface layers, the depth depends on penetrability of a
sample (different in various substances). Part of radiation is reflected by the sample
surface. Penetrated layers absorb the radiation and convert its energy into heat. Emitted
heat propagates inside the sample. Effectiveness of the propagation depends on
thermal conductivity of the sample. The better the conductivity, the faster drying process
and volatile matter evaporation. During drying process sample parameters change, its
thermal conductivity decreases so there is a risk of burning the sample. Some
parameters may be estimated “by sight”, e.g. smooth and light surfaces reflect radiation
better. This must be taken into account when setting drying parameters.
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10.3 Drawing and preparation of a sample
As sample of given substance must be representative, drawing and preparing a sample
is very important process as it affects repeatability of measurements. The most common
method of homogenizing a sample is mixing. The other method is to draw few samples
from different but specific points in a substance and calculate an average value.
Another – to draw few samples from different points in a substance, mix them and draw
a sample from the mixed samples.
Sampling method depends on the object of a research. For quality pu rpose many
representative samples are analysed. In production control it is enough to assure
sampling repeatability, which enables to study a tendency.
While preparing and drawing, it is important that the sample does not absorb moisture
from the environment – it is advised that operation time is as short as possible.
If it is necessary to analyse more than one sample at the same time, the samples
should be closed in plastic bags or other isolated containers. Give attention that
samples must not lose moisture inside the container (the container should not consist of
to much air, the moisture condensed on the sides of the container should be mixed with
the sample again).
10.4 Tools requirements
Tools and instruments used in preparation process may affect measurement accuracy,
so it is advised not to use tools that transmit heat, as it makes the sample lose moisture
before analysis.
Use only special mills and pestles.
In case of liquids with consisting of solid materials use a glass mixer, a spoon or a
magnetic mixer.
10.5 Single-use pans
To analyse the moisture, put a sample on a single-use pan and place it in the dryer
chamber.
Using non-reusable pan helps to avoid false results by remains of previous samples.
10 single use pans are provided with the moisture analyser. Any quantity may be
delivered on demand.
10.6 Placing a sample
A sample should be placed uniformly all over the pan, so that heat propagates equally
all over the sample and dries whole sample effectively and quickly without leaving “wet”
places.
Correct Incorrect
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Attention:
Due to temperature sensor localisation, max sample height is 10mm.
When substance ply is too thick, surface layers will be heated too much and internal –
not enough. This may result in burning the sample or surface incrustation, which will
make drying process difficult and measuring result false.
A sample should be placed in uniformed layers 2†5mm thick, weighing 5†15g,
depending on a substance.
10.7 Glass fibre filter
When drying liquids, pastes or substances that may melt or loose liquid during drying, it
is advised to use glass fibre filters.
Filters ensure equal liquid distribution or, in case solid materials, avoiding burning a
sample.
10.8 Selection of drying parameters to the sample material
Selection of proper temperature and drying time is essential to achieve precise humidity
measurement. Drying parameters are selected properly if repeatability is on satisfactory
level, usually between 0,11%.
Parameters choice should be made in 3 steps:
Step 1: Drying temperature is related to the physico-chemical properties of the sample.
It is determined by the number of tests carried out in several successive temperatures,
e.g., at intervals of 10 ° C. Proper temperature is the highest value for which the sample
for a few minutes does not change color and smell. Changing the color or odor indicates
the start of the oxidation of the sample, which changes the properties of the sample,
which usually affects the measurement accuracy.
Step 2: Weight of sample used should be large enough to use the entire surface of the
pan, however, the thinner the layer of sample the better the drying process proceeds.
The top and bottom layers of the material should be dried similarly at the same time. If
the material is covered with shell and some moisture is trapped in the material, user
should disintegrate the material or reduce the drying temperature. For liquid materials
is preferable to use filter which accelerates the drying.
Step 3: Select drying time to chosen mass of sample. To do this, set the moisture
analyzer‟s drying time as long as possible and observe the drying process. Minimum
drying time is the one at which the sample
doesn‟t
change its weight by more than
allowed by the examiner measurement error. Proper drying time is designated minimum
drying time with reserve. The percentage value of the reserve must exceed the mass of
the sample dispersion - the drying sample time is proportional to the mass of the
sample.
After a few measurements with the designated drying parameters and making sure that
the reproducibility of the results is satisfactory user can proceed to optimize the
measurement time by selecting favorable Drying profile and using Short measurement
mode. Of course you should check that the reproducibility of the results was not
seriously affected.
Sample values for the most common materials are given in the Appendix, however, be
regarded only as preliminary data and it is recommended to carry out the procedure for
parameters selection for the test material.
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