Frederiksen 3867.70 User manual
Description:
This demonstration multimeter has been developed
especially for teaching, and it can display the fol-
lowing quantities: Voltage, Current, Resistance,
Frequency, Temperature, Pressure and Acidity (pH).
The demonstration multimeter is supplied with a lar-
ge 4-digit display with 45 mm high illuminated digits
on the front panel. On the rear a smaller display with
14 mm high digits is provided for the teacher.
The connections for measuring Voltage, Current, Re-
sistance and Frequency are made with standard 4
mm safety jacks on the front panel. The temperatu-
re measurement is made using a type K thermo-
couple probe via the special connector designed for
this purpose. The Acidity (pH) measurement is per-
formed using a standard pH-electrode with a BNC
connector. Pressure measurements are made using
pressure sensor accessories. For thermocouple pro-
bes, pH-electrodes and pressure sensors, please
see the section on accessories.
The quantity to be measured is selected using the
rotary switch in the center of the front panel below
the display.
The instrument is supplied with an RS232 computer
interface for transferring data to a PC. This data
transfer can be performed using general communi-
cation software like hyperterminal – or the free pro-
gram Datalyse (datalyse.dk).
User´s guide for Demonstration multimeter
20.12.10 Ae 3867.70
Viaduktvej 35 · DK-6870 Ølgod Fax +45 7524 6282 www.frederiksen.eu
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Operation:
1: 4 digit display for readout.
2: Dot matrix display for displaying units.
3: Select button for confirmation of quantity cho-
sen.
4. Adjustment buttons for calibration of pH ele-
ctrode using buffer solutions, selection of mea-
suring units for pressure, temperature and ele-
ctrode measurements.
5: Connection jack for pressure sensors.
6: BNC connector for pH electrodes (or Redox
electrodes)
7: Connection jack for K-type thermocouples.
8: Rotary switch for selection of physical quantity
to be measured.
9: 4 mm safety jacks for measuring voltage, cur-
rent, resistance and frequency.
10: Fuse holder for current measurements in mA re-
gion.
The instrument is separated into 4 galvanically iso-
lated components:
Temperature
pH and pressure
Voltage, current, resistance and frequency
Serial port
This means that the demonstration multimeter can
measure several parameters at once without chan-
ging connections. This can be useful in a setup
where the instrument is used to measure current and
temperature in turn (Joule’s Law experiment). This
also means that several measurements can be re-
corded on a computer at the same time if required.
The use of the instrument is very straightforward:
just turn the rotary switch to the desired parameter,
and the display will show it. The “Adjust” buttons
can then be used to switch among various units of
measurement (Celcius, Fahrenheit, Kelvin), pH
(pH/mV).
The apparatus is connected to AC power using the
power cable supplied.
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Required accrssories:
For measurements of voltage, current, resistance
and frequency standard laboratory leads can be
used.
- Temperatur sensors:
Any K-type thermocouple sensor can be used.
We recommend:
No Type Size Range time Time
(mm) con-
stant*
3868.01 Liquid 150 x dia. 3 to 1200°C 1,3 s
3868.02 Liquid 150 x dia. 1,5 to 1200°C 1,5 s
3868.03 Liquid 197 x dia. 3 to 1200°C 1,5 s
3868.04 Surface 150 x dia. 5 to 500°C 0,95 s
3868.05 Air 185 x dia. 6 to 250°C 0,5 s
2606.53 Wire 120 cm long to 400°C
2606.52 Air 200 x dia. 8 to 250°C
2606.51 Liquid 200 x dia. 3 to 1200°C
2606.50 Liquid 105 x dia. 3 to 1200°C
*The time constant is the time required for the sensor to reach
63.2% of the measured value.
- pH-electrode:
.Any standard pH-electrode with a BNC-connector can be used.
We recommend:
5415.20 pH-electrode
- Pressure sensors:
Only the following pressure sensors can be used:
IM-131410 pressure 0-1300 hPa
IM-131510 pressure 500-7000 hPa
Connection to a PC
The Demonstration Multimeter can be connected to
a PC using a standard RS232 serial port.
Data transfer is readily managed using the program
“Datalyse”.
Accessories for connecting to a PC:
1123.05: Serial cable 25/9 pin for PC with 9-pin se-
rial port.
1123.30: USB-serial adapter for connection of the
above serial cable to a PC with a USB port
Comments on certain measurement ranges:
- Resistance:
Under no circumstances may a voltage be applied
to the V/ohm/Hz input terminal and Ground terminal
when the instrument is set for resistance measure-
ments.
- Frequency:
Frequency measurements up to 10 kHz require an
input signal of at least 1 volt. For measurements
from 10 kHz to 100 kHz a signal of at least 10 volts
is required. If no reading is observed during a frequ-
ency measurement, try increasing the amplitude of
the signal.
- pH:
If the pH measurement is selected using the rotary
switch, the instrument can also serve as a high im-
pedance millivolt-meter, e.g. for measurements with
redox electrodes or a gas chromatograph. These
options can be selected cyclically by pressing the
Adjust buttons.
- Calibration of pH electrode
The principle used is that for a given buffer solution
the pH value is selected using the Adjust buttons
and confirmed using Select. You can choose be-
tween a single or dual point calibration.
Place the pH electrode in the desired buffer solution.
Press the Select button twice. In the display you will
see: buF1. This is the single point calibration option.
If you want the two point calibration, just press one
of the Adjust buttons. The display will now show:
buF2. Confirm the calibration method you desire by
pressing Select.
The display now shows various number values fol-
lowed by the text Buf, e.g. 7.00Buf. These values are
the most commonly used standard buffer solutions
(4.00, 4.62, 7.00, 9.00 and 10.00). Use the Adjust
buttons to select the appropriate value. Execute the
calibration by pressing the Select button. A voltage
value is now shown in the display. When the value
shown is stable, press Select. This completes the
single point calibration procedure, and the display
will now show the pH value.
When the dual point calibration has been selected,
a second buffer value will be displayed. Use the
Adjust buttons as before to select the appropriate
value and confirm it by pressing Select. Rinse the
electrode in distilled water, and place it in the se-
cond buffer solution. The display will show a new
voltage value in millivolts. When the value has sta-
bilized after a few seconds, press Select to confirm.
The display will then show pH values. The dual
point calibration procedure is now completed.
If the calibration values are unusable, e.g. if the sa-
me buffer was used twice during the dual point cali-
bration, then the display will briefly show the messa-
ge: CalErr, and the previous calibration values will be
used.
Please note that the calibration is retained when the
instrument has been turned off. The same values will
be used whenever a pH electrode is selected.
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- Pressure
The Multimeter can only be used with the specified
pressure sensor accessories (see Table above).
- Calibration of pressure sensor:
The pressure sensor must be connected to the in-
strument during the calibration procedure. Press the
Select button once, and the message: ProbCal will
be shown in the display. Press Select again, and the
message: 1.000 cF will be shown. The scale factor
for the pressure sensor can now be selected using
the Adjust buttons. The new selection is confirmed
by pressing the Select button, and the display
shows the message: 0.0 Ofs. It is now possible to
adjust the zero offset for the pressure sensor by
means of the Adjust buttons. Confirm the selection
by pressing Select. The instrument will then change
to the measurement mode and show the current
pressure reading. Note that the calibration factors
are stated on a label on each pressure sensor.
- Menu:
This option is intended for use with special facilities,
e.g. for connection to a PC. In the current version of
the Multimeter this option has not been implemen-
ted.
Technical data
Supply voltage:
230VAC +/-10%
Power consumption: 20 W
Front panel display: 4-digit 7-segment LED,
45 mm hih
Units display: 7x15 LED matrix
Bagdisplay: 4-digit 7-segment LED,
13 mm high
Fuse for current mA-range: 2A (slow)
(4090.21)
Current limiter: A-range - electronic limit with
warning display
Fuse for grid: 315mA (slow) (4090.36)
(Located in fuse holder on back panel)
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Measurement Range Accuracy Input impedance
DC Voltage 0 – 500V 0.5% + 1 digit 10MΩ
AC Voltage 20mV – 500V 10Hz – 1kHz: 1% + 1 digit 10MΩ
1kHz – 2kHz: 2% + 2 digit
2kHz – 5kHz: 5% + 2 digit
5Hz – 10kHz: 10% + 2 digit
DC Current 0 – 10A 0.5% + 1 digit 10Ω; 0.1Ω; 0.01Ω
AC Current 20µA – 10A 10Hz – 10kHz 1% + 2 digit
Resistance 0 – 10MΩ1% + 1 digit
Frequency * 0 – 100 kHz 0.5% + 1 digit 10MΩ
Temperature -200°C – 1370°C 0.1% + 1 digit
Pressure 0 – 7000 hPa 0.1% + 1 digit
pH 0-14 0.1% + 1 digit >10GΩ
* Frequency measurements up to 10 kHz require at least 1 volt; from 10 kHz to 100 kHz require at least 10 volts.
