N = LSB of the measurement value
X = measurement value (the corresponding value for the
final value of the measurement range is 200 bits)
R = range (4 bits in total)
0001
1 kV/m
0010
10 kV/m
0100
100 kV/m
V = sign of the measurement value (1 = negative, 0 =
positive)
Normal measurement values are recognised by the fact that
the MSB (bit 7) of byte 1 always has the value "0". If, on the
other hand, the MSB is "1", an important information is
transmitted together with the corresponding measurement
value.
6
EXPERIMENTAL LITERATURE
Experimental units in Physics:
The electric field, 1, (in German)
16100.01
The electric field, 2, (in German)
16100.11
7
TECHNICAL DATA
Operating voltage
14 18V DC
Current consumption
< 200 mA
Output resistance
1 k
Ω
Output voltage
± 10 V DC
Short-time drift
< 1 %/h
Operating temperature
10 40 °C
Permissible atmospheric
humidity
up to 65% r. H.
Housing dimensions in mm
70 x 70 x 150
Support stem
d
= 10 mm,
l
= 145 mm
Weight
0,67 kg
Field measurement
Measuring ranges
1/10/100 kV/m
Precision (calibrating set-up
according to fig. 2)
± 3%
Voltage measurement
Measuring ranges
10/100/1000 V DC
Accuracy
2)
± 3%
Input resistance
approx. 10
16
Ω
Input capacitance
approx. 10 pF
8
ACCESSORIES
Analogue demonstration multimeter ADM 2
13820.00
Capacitor plate with hole,
d
= 55 mm
11500.01
Set-up capacitor, large
06233.00
Power supply, universal
13500.93
or
Double power supply
13520.93
9
WARRANTY INDICATION
We grant a 6 months warranty on the unit supplied by us.
This does not cover normal wear or damages due to wrong
use.
The manufacturer only is responsible for function and safety
characteristics of the unit if maintenance, repairs or
modifications to the latter were carried out either by the
manufacturer himself or by an institution expressly
authorised by him.
which insulated conductors, e.g. conductor spheres, are
mounted. Not only is the insulation resistance reduced by
contamination or a film of moisture, but also charges, which
falsify the measurement, are often to be found on these
stems. It is therefore advisable to clean the stems before
use in lukewarm water with a detergent additive. After
drying, they can be held in clamps if necessary, so that
renewed contamination through handling is avoided. To
remove charges from the stems, they can be passed once
or twice over a flame, which will at the same time remove
any remaining moisture film. However, they should not be
too intensely heated, since otherwise the Plexiglass could
be distorted. This flame treatment should also be carried
out now and then during a measurement series and
freedom from charges should be checked with the EFM.
5
DESCRIPTION OF THE DATA INTERFACE
A PC can be connected to the unit by means of the supplied
data cable, in order to assure data output. Connection is
carried out directly to a 9 pole serial (RS232) interface
output of the computer. For connection to a computer with
25 pole connector, a commercial adapter is required.
The supplied cable has the following pin allocation, which is
the same for both connectors:
RxD
=
2
DTR
=
4
RTS
=
7
The shielding is cut off at one of the two plugs in order to
avoid equipotential bonding currents between the computer
and the unit. In case of problems with data transfer, it must
be checked if the used cable actually is the one supplied
with the unit.
A simple programme to output measurement values is
supplied with the unit. If necessary, please ask us for the
actual status of available software.
5.1 Information for the programmer
The following interface description only is relevant for users
who wish to create their own programmes. This in any case
will require good knowledge of the RS232 interface.
RTS = 1 and DTR = 0 must be set on the computer for the
interface to work. The data will then be received at xx286,
whose serial interface is set as follows: 9600 Baud, 8
Databit, no parity, 1 Stopbit.
The unit transmits measurement data every 100 ms. These
always consist of 2 bytes following each other immediately.
In order to differentiate, the LSB (bit 0) of the 1st byte
always is "1" and the LSB of the 2nd byte always is "0". The
measurement values are transmitted with a resolution of 8
bits and a supplementary bit for the sign. The first 7 bits are
in the second byte, whereas the last bit of the first byte is
transmitted as the last but one bit (bit 1). The other bits of
the first byte give information concerning the set
measurement range and the differentiation between cases
related to the output measurement value according to the
following table:
The designation of the single bits means:
4
11500.10
1
st
Byte
2
nd
Byte
Value
Moment in time
0VRRRRN1 XXXXXXX0
Meas. value
every 100 ms
1V0010N1 XXXXXXX0
Meas. value
Switching off
1-0110N1 XXXXXXX0
Operating voltage
Voltage too low
1V1010N1 XXXXXXX0
Meas. value
Functional error
1V1110N1 XXXXXXX0
Operating voltage
Switching on
