Gehaka G939 User manual

User Manual
Grain moisture meter – model G939
Version: 1.00.000
Date: 08/2013

Summary
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
G939 installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Measuring – Moisture measuring . . . . . . . . . . . . . . . . . . . . . .
1.1 Diagram of the functions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 2. Conguration . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Date and Ttime adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Adjusting the number of elements to be averaged . . . . . . . . . .
2.3 Adjusting the number of decimal digits . . . . . . . . . . . . . . . . . .
2.4 Adjusting the print mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 Adjusting number of report copies . . . . . . . . . . . . . . . . . . .
2.6 Adjusting the contrast . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.7 Unlocking chamber door . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.8 Uploading Internet equation . . . . . . . . . . . . . . . . . . . . . . . .
2.9 Uploading standard equation . . . . . . . . . . . . . . . . . . . . . . .
2.10 Self-report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.11 Language selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 RS232 Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Thermal printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5 Extreme conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 3.6 Technical specications . . . . . . . . . . . . . . . . . . . . . . . . .
3.7 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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4I Grain Moisture Meter – Model G939
The G939 moisture meter includes all the characteristics to provide the most accurate
grain moisture reading.
With a simple operation and without operator intervention, model G939 will provide
moisture readings in a few seconds, for a wide variety of products.
With a simple 5-key keypad, the instrument can be easily operated and set up, without
intensive user training.
By applying the “FLOW THRU” technology, G939 provides a fully automatic moisture
analysis. There is no need of previous sample weighing; temperature, density and
weight corrections are performed automatically, without the use of any other resource
or additional tables.
Calibration curves for each cereal have been obtained at Gehaka laboratories, using
samples collected from several areas of the plantation. Using the standard oven method
as a reference, measurement scales for each product were developed. These curves
weretransferredtotheG939memoryandtheyareeasilyidentiedbyproductname
and their version.
If the development of new calibration curves is necessary, there is a function at www.
moisturetester.com.br which allows creating, editing and installing them in your G939
grain moisture meter.
G939 includes three instruments into one,
managed by a state-of-the-art internal
microprocessor. These three instruments
are: One electronic scale, which measures
the sample weight; one built-in digital
thermometer, which measures the sample
temperature inside the chamber and the
G939temperatureandnallyonecapacity
meter, which indicates the moisture
percent, to be later corrected by other
parameters.
Introduction

Grain Moisture Meter – Model G939 I5
Its program performs all the required calculations, thus providing extremely reliable
and repeatable readings. It also performs: automatic setting and checking the proper
operation of all electronic circuits.
The meter’s FLOW THRU design allows the performance of quick measurements, namely,
in less than 15 seconds and without the operator intervention, in a fully automatic way.
Just select the product, pour the sample in the G939 hopper, until a “BEEP” is given,
the G939 will load the sample, perform the measurement and automatically unload the
sample. After a few seconds, you will have the moisture and temperature measurement,
all this shown on an easy to read 16-character / 2-line alphanumeric LCD display, in
Portuguese.
G939 has also a bidirectional RS232C serial communication port. With this, we can
connect the G939 to a printer so the measurement is printed in a label, thus making
the counterchecking easier, or else, we can connect the meter to a PC and transfer the
information to a managing system.
The G939 is operated by a FULL RANGE automatic power source, which means the meter
operation is ensured for 90 – 240 VAC mains, thus protecting the meter from network
voltage variations.
Indication conventions for G939 LCD display:
> Right-hand arrow
< Left-hand arrow
YES Option acknowledgment
ESCAPE Exit

6I Grain Moisture Meter – Model G939
Description
1. SAMPLE LOADING HOPPER
Place where the cereal sample, to
have the moisture measured, will be
weighed.
2. LCD DISPLAY
Displays results and settings with
alphanumeric characters.
3. THERMAL PRINTER (OPTIONAL)
Device for printing measurement
results. Silent, low consumption
operation.
4. DRAWER
Receives the cereal sample from the
chamber, after the measurement
was performed. The meter unloads
automatically.
5. PLASTIC SCOOP
Used for pouring the sample into the
funnel.
6. ON/OFF
Switches ON/OFF the G939 meter.
Operating with numerical setting
multiplies by 10 the indicated value.
7. YES
 Conrms function or setting
selection.
8. RIGHT-HAND ARROW
It displays the next function or
increases the value of one scale
interval.

Grain Moisture Meter – Model G939 I7
9. LEFT-HAND ARROW
Displays the previous function or
decreases the value of one scale interval.
10. ESCAPE (EXIT)
Exits a function or setting that is being
operated at that time. Operating with
numerical setting divides by 10 the
indicated value.
11. POWER CORD CONNECTOR
Place where the power cord will be
connected. G939 operates between 90
and 240 VAC.
12. CARRYING HANDLE
Used for carrying the G939. Caution:
before lifting the G939 remove the drawer,
because due to the tilt it may fall down.
13. RS232 SERIAL PORT CONNECTOR
Data output for printer or PC.
14. HARD LOCK
When connected to RS232 serial output,
it releases access to “Conguration”
function, where G939 congurations will
be made.
Adjusting a value
In addition to the direct functions of the keypad, it can assume other functions, and one
of them is making easier to type a value.
When the setting of a value is selected, the display will show the current value, and to
change it proceed as follows:
KEY FUNCTION
ON/OFF Multiplies the current value by 10;
RIGHT-HAND ARROW Increases the indicated value by one scale interval;
LEFT-HAND ARROW Decreases the indicated value by one scale interval;
ESCAPE (EXIT) Divides by 10 the current value;
YES    Conrmsthecurrentvalueandcompletesthesetting.

8I Grain Moisture Meter – Model G939
Carefully check the packing, if there were marks and damages in the cardboard case,
this means that there were problems during shipment.
Open the packaging, checking the conditions of G939. Remove the equipment and check
whether all its accessories are included.
Place the G939 on a stable table, in order to ensure it will not move during the operation.
Remove the adhesive tapes fastening the drawer and check whether it slides easily.
If the acquired model features a Thermal Printer, install the paper roll as stated in
procedure “3.2 Thermal Printer”.
ConnecttheACcordtotheconnectorontherearpanelandtitsteadily,takingcare
that the plug is fully inserted in the connector. It is not necessary to verify the mains
voltage; the power supply is FULL RANGE, not requiring mains selection. We also do not
recommend the use of voltage stabilizers.
When the cord is plugged in the outlet, G939 will start its operation, performing a self-
diagnosis in order to check whether its components are working properly. If by any
chancethemeterveriesthatsomeofitscomponentsisimproperlyoperating,itwill
indicate an error message on the display regarding the fault.
Leave the G939 meter preheating for 10 minutes. The G939 meter shall operate
continuously plugged in the outlet; use only the ON/OFF key. This way, the equipment
enters the “sleeping” mode and the power consumption is lower than 1 W, however it is
ready to operate.
The G939 meter shall be operated in a place free of excessive dust and with room
temperature between 0º and 40 ºC.
G939 installation

Grain Moisture Meter – Model G939 I9
Te m p. 2 4.8 oC
Sample: 21 >
1. Select“Measuring”fromthemainmenu,depressYEStoconrm;
2. Select the type of cereal you want to measure the moisture. Use Right hand/
LefthandARROWkeysuntilndingthedesiredproduct.Indicationsbelowthe
product names are the moisture minimum and maximum limits the G939 meter
isabletomakethereading.Depress“YES”toconrmyourchoice.
3. Take a sample of at least 200 g of the product you want to measure the moisture
and, using the plastic scoop, slowly pour the cereal sample into the loading
hopper, until the 100% is shown on the display, a beep will be heard indicating the
sample weight is correct. If by any chance the weight is exceeded, the display will
show a value higher than 100%, and the sample excess shall be removed from the
hopper.
4. Within a few seconds, the G939 meter will display the value of product moisture.
If the Right hand/Left hand keys are depressed, the G939 meter will display all the
measurements made, namely:
When selecting Right hand/Left hand Arrow we have:
1. Measuring – Moisture measuring
WHEAT
MOIST.: 13.09%
Sequence number of the measured sample.

10 I Grain Moisture Meter – Model G939
5. After having performed a successful measurement, the G939 meter will send all
measurement data through the serial output to the printer or PC. An example of
report follows:
================================
GEHAKA G939
Fir m w a r e Versio n 0.60.006
Hardware Version 1.00
Serial No. 12345678901234
================================
Current Product..= Wheat
Equation Version.= 20111101
S a m p l e ..........= 2 9
Sample Temp…………..= 24.9 ºC
M e t e r T e m p.......= 2 5.5 ºC
Sample Weight……..= 142.5 g
--------------------------------
M o i s t u r e ........= 1 3.0 5 %
--------------------------------
--------------------------------
Signature 11:02
Responsible person 21/01/13
NOTE: Ifthereisagreattemperaturedierencebetweentheproductand
theG939Hopperwherethetemperaturesensorislocated,themeter
willwaituntilthereisathermalbalancebetweenbothofthem.This
could introduce a delay for the temperature measurement to be
made.This way,we improvethemeterprecision,bymeasuring the
actual sample temperature.
6. When the G939 meter is showing the measurement results on the display and
a new sample is poured into the hopper, the G939 meter will perform a new
measurement,usingthesamecongurationofthepreviousmeasurement.Ifthe
ESCAPE key is depressed, the MEASUREMENT option will be exited, returning to
the MAIN menu.
7. After the measuring cycle, the instrument will unload the sample into the drawer.
NOTE: Ifthemoisturecontentishigherthan22%,theG939meterwillrequest
measuringagainthesamesample,repeatingthemeasurementthree
times in order to ensure a higher reading precision.

Grain Moisture Meter – Model G939 I11
1.1 Diagram of the functions
A diagram follows indicating all G939 meter functions and it will help to understand the
operation.

12 I Grain Moisture Meter – Model G939
The“Conguration”modeoersthepossibilitytomakesettingsorcongurationsinthe
G939 meter. Now, we will describe each one of these functions.
Note that the number shown before each function corresponds to the same shown in
the G939 Menu, this way it is easier to identify in the manual where the explanation of
each function is.
If the Hard Lock key is not connected to the G939 Serial
Port and the access to this function is attempted, the
display will show an error message “Access locked, Use
the Hard Lock” stating the need of the key presence.
If you wish, remove the key after entering the
“Conguration”,thereisnotanewchecking.Whenyou
exit the function, it will be locked again.
G939 settings and Equations can only be changed
with the presence of the Hard Lock key, this ensures
improved security.
This function makes the Date and Time adjustment of the real time clock (RTC). This
value of date and time will be sent in the reports through RS232 Serial Port after the
measurement.
G939 is already delivered with the clock adjusted at the factory, but it may eventually be
readjusted for the Daylight Saving Time.
There is an internal battery that keeps the clock working even when the G939 meter
is disconnected from the outlet. This battery lasts for over 5 years; to have it tested,
just disconnect the G939 meter and see if the clock indicates 00:00:80, if this happens,
contact Gehaka service to replace the battery.
2. Conguration
2.1 Date and time adjustment

Grain Moisture Meter – Model G939 I13
To perform the Date and Time adjustment:
1. Goto“Conguration”anddepressYES;youhavetoputtheHardLockintheserial
output;
2. Go to function “2.1 Date and Time Adjustment” and depress YES;
3. Now use the Right hand/Left hand ARROWS to Increase or Decrease the value of
the TIME. When the value is right, depress YES and the G939 will go to the next
eldtobeadjusted;
4. Repeat this procedure for adjusting MINUTES, DAY, MONTH, and YEAR.
NOTE: Thevaluebeingadjustedwillbeshownunderlined,afterdepressing
YESitwillgotothenextitemtobeadjusted.
This function adjusts the number of elements to be used for making the average of
readingsusedtocalculatethenalvalueofmoisturepercent.Wecanselectbetween1
and 5 elements.
To adjust the number of Elements to be Averaged:
1. Goto“Conguration”anddepressYES;youhavetoputtheHardLockintheserial
output;
2. Go to function “2.2 Adjusting the Number of Elements to be Averaged”, and
depress YES;
3. Now use the Right hand/Left hand ARROWS to Increase or Decrease the Number
of Elements to be Averaged. This adjustment is limited between 1 and 5 elements;
4. Depress YES to complete the adjustment.
NOTE: Itshouldbenotedthat,irrespectiveoftheadjustmentmadeinthis
function, when the moisture co content exceeds 22% there will be
alwaysmadeareadingaveragingofthreeelements.
2.2 Adjusting the number of elements to be averaged

14 I Grain Moisture Meter – Model G939
This function makes the adjustment of the decimal digits shown on the display and in
the moisture reports. If one decimal digit is used, the rounding of the second decimal
digit will be automatically made. The factory default setting is one decimal digit.
To adjust the number of decimal digits:
1. Goto“Conguration”anddepressYES;youhavetoputtheHardLockintheserial
output;
2. Go to function “2.3 Adjusting the Number of Decimal Digits”, and depress YES;
3. Now use the Right hand/Left hand ARROWS to increase or decrease the number
Decimal Digits. This adjustment is limited between 1 and 2 decimal digits;
4. Depress YES to complete the adjustment.
2.3 Adjusting the number of decimal digits

Grain Moisture Meter – Model G939 I15
This function sends the measurement data to a Printer or PC.
A. Printer:
In this mode, measurement data in a report format will be sent, as stated below, through
the serial port RS232.
If the G939 meter has a built-in thermal printer, this report will be printed and
simultaneously sent through the serial port RS232.
================================
GEHAKA G939
Firmware Version 1.00.000
Hardware Version 1.00
Serial No. 12345678901234
================================
Current Product..= Wheat
Equation Version = 20111101
S a m p l e ..........= 4
Sample Temp…………..= 27.7 ºC
M e t e r T e m p.......= 2 7.5 º C
Sample Weight……..= 141.5 g
--------------------------------
M o i s t u r e ........= 1 2.4 2 %
--------------------------------
--------------------------------
Signature 13:00
Responsible person 18/01/13
================================
B. Computer:
The Computer Mode just sends the data, without considering formats. The data
is separated by “;” in order to make the separation easier. This report may be easily
captured and interpreted by a computerized system connected to the RS232 serial port.
Forthisfunction,iftheG939meterhasabuilt-inprinter,itwillbeswitchedobythe
G939 and will not print this data.
2.4 Adjusting the print mode

16 I Grain Moisture Meter – Model G939
See below an example of the string that is sent. The ending is with CR and LF.
15; 12.35; 141.7; 77.0; 26.9; 27.4; 66.4; Wheat;
20111101;G810; 1.00.000;1.00; ”1234567891234”; 16:51; 18/01/13;
Descrição dos campos dos dados enviados:
Sample number;
Moisture;
Weight;
Density;
Sample Temperature;
Instrument Temperature;
S c a l e _ A ( C a p a c i t a n c e );
Product Name;
Equation Version;
Instrument Model;
Fir m ware Version;
Hardware Version;
Serial number;
Ti m e;
Date;
CR + LFCR + LF
To perform the print mode selection:
1. Goto“Conguration”anddepressYES;youhavetoputtheHardLockintheserial
output;
2. Go to function “2.4 Adjusting Print Mode”, depress YES;
3. Use Right hand/Left hand ARROW keys to select between the two printing modes,
Printer or Computer;
4. Depress YES to complete the adjustment.

Grain Moisture Meter – Model G939 I17
This function allows adjusting the number of copies that will be printed after each
moisture measurement.
This function allows adjusting the contrast of the LCD display.
This value can be adjusted between 55% and 100%, and 100% is the maximum contrast.
This value will be stored in the G939 memory.
To adjust the Contrast:
1. Goto“Conguration”anddepressYES;youhavetoputtheHardLockintheserial
output;
2. Go to function “2.5 Contrast Adjustment” and depress YES;
3. Use the Right hand/Left hand ARROWS to increase or decrease the Contrast
value. This adjustment is made in 5% steps;
4. Depress YES to complete the adjustment.
2.5 Adjusting number of report copies
2.6 Adjusting the contrast

18 I Grain Moisture Meter – Model G939
When measuring products such as rough rice,
soybean bran, etc., the Chamber may accumulate
residues, especially when such cereals are very dry
with a low relative humidity.
Before performing the cleaning, the Chamber Door
shall be unlocked, if it is attempted to open the
door without using this function, the G939 chamber
could be damaged.
To open the door and performing the cleaning:
1. Go to “Conguration” and depress YES;
you have to put the Hard Lock in the serial
output;
2. Go to function “2.6 Unlocking Chamber
Door”, and depress YES;
3. Use the LEFT HAND ARROW to open the
door; the G939 will emit the typical noise of
the Chamber Door opening;
4. Disconnect the AC Cord from the G939 rear
panel;
5. Put down horizontally the G939 as shown in
the photo;
6. Carefully perform the Chamber cleaning;
7. Connect the G939 again for operation.
2.7 Unlocking chamber door

Grain Moisture Meter – Model G939 I19
One great innovation of G939 is by the use of the Internet, performing a customization
of the products the G939 will measure. All this information and the guidance to execute
them may be accessed at www.moisturetester.com.br.
2.8 Uploading internet equation
Provider
INTERNET
Site:
www.moisturetester.com.br
GEHAKA
RS232
Basically we can:
• Register the G939. This register entitles to an extension of six months of the
Warranty; do not lose this opportunity. It also allows us to know which scales are
more important to you, and allows us to keep you informed about new updates,
includingimprovementsinG939rmware.
• Selecting which products will be sampled by G939. With this, the time for changing
scale is reduced, thus making the operation easier. Also a backup of the G939
Equations in the cloud will be made, thus ensuring their return to the instrument,
even if it were totally damaged.
• Updating the equations as soon as they are reviewed. Gehaka works around
the year reviewing scales of the G939 meters, or developing new ones, however,
before the equipment had to be carried to the Service to receive these updates.
Now with the use of the Internet you will receive an e-mail telling that there was
a review of a Product that is in your equipment and, in a few minutes, connected
to a PC, it can be updated.

20 I Grain Moisture Meter – Model G939
• Creating new Equations. It is possible, starting from a “Universal Scale”, to create
a new equation for a product the G939 does not have. Just set up a table with the
readings of the Standard and those obtained in the G939 and in a few minutes
you will create a new Equation and you will be able to install in the G939. Through
our website you will get all the support and guidance for the creation.
Connecting the G939 to a PC is quite simple: Just follow the steps below:
1. The computer must be connected to the Internet, otherwise it will not be possible
todownloadthenecessarylesfortheinstallation;
2. Find an unused USB port in the PC;
3. Connect the Serial Cable supplied with the G939 to the USB port, do not still
connect to the G939;
4. Wait for the driver installation, this could take up to 5 minutes, depending on
theInternetbandwidth.ThisstepwillonlybeexecutedthersttimetheCable
is connected to the PC, after this the PC will automatically recognize the Serial
Cable;
5. Connect the G939;
6. Place the Hard Lock in the Serial Port of G939;
7. Selectthe“Conguration”functionanddepressYES;
8. elect the “2.8 Uploading Internet Equation” function;
9. Remove the Hard Lock and connect the Cable in the Serial Port of G939;
10. Access the website www.moisturetester.com.br and click on the “Moisture
Meter”.
11. From now on, follow the instructions shown in the PC, which assumes the control
of G939. All the operations stated in the site may be performed.
12. Register your G939, this will bring many advantages.