Metrohm 776 Dosimat User Manual
CH-9101 Herisau/Switzerland
Tel. +41 71 353 85 85
Fax +41 71 353 89 01
E-Mail sales@metrohm.ch
Internet http://www.metrohm.ch
776 Dosimat
Instructions for Use
8.776.1023
2005.06 ti/dm
Content
776 Dosimat
Content
1 Overview ...................................................................................................................2
2 Operation with the keyboard ...................................................................................4
2.1 Keypad........................................................................................................................ 4
2.1.1 Key <RATE> .......................................................................................................6
2.2 Modes ......................................................................................................................... 6
2.2.1 Mode DOS, dosing ..............................................................................................7
2.2.2 Mode DIS R, repetitive dispensing....................................................................... 9
2.2.3 Mode DIS C, cumulative dispensing.................................................................... 9
2.2.4 Mode PIP, pipetting............................................................................................ 10
2.2.5 Mode DIL, diluting..............................................................................................11
2.2.6 Mode CNT D, content dispenser .......................................................................12
2.3 User memory ............................................................................................................17
2.4 Special settings.........................................................................................................18
3 Error messages, troubleshooting..........................................................................19
3.1 Special messages and error messages ................................................................... 19
3.2 Diagnosis ................................................................................................................. 21
3.3 RAM initialisation....................................................................................................... 29
3.4 Releasing a locked spindle with insertd Exchange Unit...........................................30
4 Appendix.................................................................................................................31
4.1 Technical specifications............................................................................................ 31
4.2 Warranty and certificates ..........................................................................................33
4.2.1 Warranty ............................................................................................................. 33
4.2.2 Certificate of Conformity and System Validation................................................ 34
4.3 Scope of delivery and ordering designations ...........................................................36
Index...........................................................................................................................37
Overview
776 Dosimat
1
Explanation of symbols:
< > means "key", e.g. <GO> means key "GO"
DOS.....0.000 ml means "display"
Overview
776 Dosimat
2
1 Overview
Front view of instrument:
1 Exchange unit
Normally the models with automatic cock changeover.
Note:
Choose the volume of the Exchange unit in such a way that a volume between
10...100% of the nominal volume is expelled.
2 Display
The 16 digit display shows all important information:
DOS 3.456 ml Mode (DOS = dosing) and dosed volume. Dosimat is in
stand-by position
DOS ↑ 3.456 ml The piston is moving upwards.
DOS ↓ 3.456 ml The piston is moving downwards.
DOS → 3.456 ml The cock is turned to the right.
DOS ← 3.456 ml The cock is turned to the left.
The display of the status
↑ resp.↓ are specially important for very slow dosings
where movements of the piston cannot be clearly identified.
3 Operating keys at the Dosimat
<FILL> Filling. This key is always accessible and serves also as
emergency stop.
<CLEAR> Resetting of the volume display to 0 with Dosimat in stand-by
position.
<GO> Order to execute the current mode. With mode DOS, dosing
goes on as long as <GO> is pressed.
4 Setting of display contrast
5 Analogue setting of dosing rate
Position 1 = lowest rate
Position 10 = highest rate
The expelling and filling rates can be set separately (see page 6).
Overview
776 Dosimat
3
Rear view of instrument:
6 Connection for keyboard
For details of operation with keyboard 6.2149.000 see page 4ff.
7 Power connection
In power supply systems, in which strong HF interferences (transients) are superimposed on the power voltage, the 776 Dosimat should be connected via an
additional power line filter, e.g. METROHM 615 model.
The main cables supplied with the instrument are three-core and equipped with
a plug with an earthing pin. If a different plug has to be fitted, the yellow/green
lead must be connected to the protective earth. Each break in the earthing inside
or outside the instrument can make it a hazard.
When the instrument is opened or if parts of it are removed, certain components
may be live if the instrument is connected to the power line. The power cable
must therefore always be unplugged when certain adjustments are made or
parts replaced.
8 Power switch
Switching on and off Dosimat. The 776 Dosimat is equipped with a non-volatile
memory, i.e. set parameters remain in the working memory if the Dosimat is
switched off and on.
9 Earthing socket
The 776 Dosimat must be grounded correctly and effectively, if necessary
through the separate earthing socket.
10 Connection for stirrer
In general a Magnetic Stirrer (forms a complete titrating stand). Other stirrers
may be connected as well, e.g. a METROHM Rod Stirrer. Supply voltage output:
+9 V DC (I # 200 mA).
11 Connection for external dosing contact
E.g. 6.2107.000 push button cable.
12 Indication of power voltage
Make sure the current has been adapted correctly before Dosimat is switched
on.
13 Identification plate
Indication of model, series and serial number.
2.1. Keypad
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2 Operation with the keyboard
2.1 Keypad
6.2149.000
SMPL
9
BLANK
7
FACTOR
8
RATE VOLUME EXP
ENTER
FILL
GO CLEAR
RECALL
6
STORE
5
UNIT
4
3
2
1
MODE
–
.
0
RATE Expelling and filling rate in all modes.
VOLUME Different volumes depending on selected
mode.
EXP Exponent.
BLANK
FACTOR Calculation parameters in mode DOS.
SMPL
UNIT Unit in modes DOS and CNT
STORE Management of user memory:
RECALL Storing, loading of modes.
MODE Selection of mode.
ENTER Confirmation of entries.
FILL Filling and emergency stop key.
CLEAR Resetting of the volume display to 0 with
Dosimat in stand-by position.
GO Start mode. With mode DOS, dosing
goes on as long as <GO> is pressed.
The keys <FILL>, <CLEAR>, <GO> are identical
with the corresponding keys on Dosimat.
2.1 Keypad
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Rules for data input:
• On entering a negative number, key in minus sign first; <-> is not a "change of sign"
key!
• Changeover between first functions (blank, factor etc.) and digits is done
automatically.
• Terminate parameter entries with <ENTER>.
• Some keys are organized as inquiry drums, i.e. pressing these keys several times, dis-
play shows new inquiries. A new value is stored or a new feature is selected with
<ENTER>. The program then returns to the initial state, the inquiry drum is left. Entering an inquiry drum, that inquiry, where the drum has been left last time, is displayed
first.
• The Dosimat works with a resolution of 10'000 pulses per burette cylinder volume. The
resolution on the display is therefore depending on the mounted Exchange unit.
Exchange unit
Resolution of display
Volume/mL Rate mL/min
Smallest increment
V
1 mL .001 .001 0.1 µL
5 mL .001 .005 0.5 µL
10 mL .001 .010 1 µL
20 mL .002 .020 2 µL
50 mL .005 .050 5 µL
If a volume value is entered which can not be dosed exactly with the Exchange unit
mounted, the value is rounded off to the next possible one and stored accordingly.
• Key <CLEAR> sets parameters to "OFF".
2.2. Modes
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2.1.1 Key <RATE>
The inquiries of this key are identical for all modes.
Expelling and filling rate
This key is accessible live (except in mode DOS), i.e. rate can be
changed during a running function .
↑ ml/min
Expelling rate
Range for digital setting depending on volume of Exchange unit:
1 mL 0.001 3.00 mL/min
5 mL 0.005 15.0 mL/min
10 mL 0.010 30.0 mL/min
20 mL 0.020 60.0 mL/min
50 mL 0.050 150.0 mL/min
Key <CLEAR> sets "OFF", i.e.. the rate can be controlled
analogically by means of potentiometer at the Dosimat 776.
If the preset rate is too high to be dosed with the Exchange unit
presently mounted, the rate is set automatically to its maximum.
↓ ml/min
Filling or aspirating rate
The data input rules are the same as for the expelling rate.
The filling rate is set to maximum on changing the Exchange unit
(e.g. always after no exch. unit! is displayed!).
2.2 Modes
The modes are selected by the inquiry drum <MODE> and
confirmed with <ENTER>.
DOS: DOSing
Dosimat is dosing as long as <GO> is pressed. Result calculation
can be activated.
DIS R: DISpensing, Repetitive
Dosimat is dosing a stored dispensing volume if <GO> is pressed,
the burette cylinder is refilled and display reset to 0.000 mL.
DIS C: DISpensing, Cumulative
Dosimat is dosing a stored dispensing volume if <GO> is pressed,
the dispensed volume (V-DIS) remains displayed.
PIP: PIPetting
Aspirating and subsequent expelling of a stored pipetting volume.
DIL: DILuting
Aspirating a stored pipetting volume and subsequent expelling of the
pipetting and diluting volume.
CNT D: CoNTent Dispenser
Preparation of solutions with preselected content.
RATE
MODE
2.2 Modes
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Example:
Selection of mode "DIS C", cumulative dispensing.
Press <MODE>.
Display shows that mode which has been selected last with key <MODE>, e.g.
DOS .
Press <MODE> repeatedly until display shows DIS C .
Load mode "DIS C" into working memory with <ENTER>.
Display shows DIS C 0.000 ml.
Mode "DIS C" is ready to work, the piston is in zero position.
All modes which are loaded into the working memory by key <MODE> are equipped
with a set of standard parameters:
Mode V-DIS/V-PIP
mL
V-LIM/V-DIL
mL
Rate
↑
mL/min
Rate ↓
mL/min
Calculation
DOS – OFF OFF max. b=0; f=1; s=1
DIS R 1 – OFF max. –
DIS C 0.1 OFF OFF max. –
PIP 0.1 – OFF OFF –
DIL 0.1 1 OFF OFF –
CNT D – – OFF max. –
2.2.1 Mode DOS, Dosing
Dosimat is dosing as long as <GO> is pressed. Result calculation can be activated.
V-LIM OFF ml
Security volume:
Dosing is stopped if V-LIM has been reached.
Input range: 0.001...999.999 mL, OFF
Expelling and filling rate, see page 6.
VOLUME
RATE
2.2. Modes
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Calculation values
b = 0. ml
Blank value
Input range: 0...±999.999 mL
f = 1.
Factor
Input range: 0... ±1E33
s = 1.
Sample size
Input range: 0... ±1E33
unit
Unit
Input range: ppm, %, g, mg, g/L, mg/L, mol, mol/L, mL, L,
/pc, none
Result calculation
If one of the calculation values (blank, factor, smpl) is not set to its standard value, a
result is calculated on filling of the Dosimat according to formula:
(dosed volume – blank)*factor
Result = ————————————————
smpl
The result is recalculated on each entry of a calculation value (blank, factor, smpl).
Pressing <CLEAR> display shows the dosed volume in mL. To start a new dosing, press
<GO> twice, pressing once resets the volume in display to 0.000 mL.
7
BLANK
SMPL
8
FACTOR
UNIT
9
4
2.2 Modes
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2.2.2 Mode DIS R, Repetitive Dispensing
Dosimat is dosing a stored dispensing volume if <GO> is pressed. The burette cylinder
is refilled and display reset to 0.000 mL.
V-DIS 1. ml
Dispensing volume
Input range: 0.001...999.999 mL
Expelling and filling rate, see page 6.
2.2.3 Mode DIS C, Cumulative Dispensing
Dosimat is dosing a stored dispensing volume if <GO> is pressed, and the dispensed
volume (V–DIS) remains displayed.
V-DIS 0.1 ml
V-LIM OFF ml
Dispensing volume
Input range: 0.001...999.999 mL
Security volume
Dispensing is stopped, if V-LIM has been reached.
Input range: 0.001...999.999 mL, OFF
Expelling and filling rate, see page 6.
VOLUME
RATE
VOLUME
RATE
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