24
…7
PROGRAMMING AND ELECTRICAL CALIBRATION
e
p
y
T
t
n
e
m
u
r
t
s
n
I
l
a
n
i
m
r
e
T
d
e
t
n
u
o
M
ll
a
W
1
2
3
4
5
6
7
d
e
t
n
u
o
M
l
e
n
a
P
2
1
1
1
0
1
9
8
7
6
t
n
e
r
r
u
c
e
v
+
t
u
p
n
i
t
n
e
r
r
u
c
e
v
–
t
u
p
n
i
t
u
p
n
i
0
0
0
1
T
P
o
t
k
n
i
L
)
6
(
7
l
a
n
i
m
r
e
t
t
u
p
n
i
0
0
0
1
T
P
7.6
Electrical Calibration
Note.
The instrument is calibrated by the company prior to despatch and an electrical calibration should be carried out
only
if
the accuracy of the instrument is suspect
and
suitably calibrated test equipment is available.
7.6.1
Equipment Required
a) Current source: 0 to +100 µA.
b) Decade resistance box (temperature input simulator): 0 to 1k5 .
c) Digital milliammeter (current output measurement): 0 to 20 mA.
Note.
Resistance boxes have an inherent residual resistance which may range from a few milliohms up to 1 ohm. This value must
be taken into account when simulating input levels, as should the overall tolerance of the resistors within the boxes.
7.6.2
Preparation
a) Switch off the supply and disconnect the sensor, temperature compensator and current output from the electronics unit terminal
block – see Fig. 3.5 or Fig. 3.6.
b) Connect the current source / resistance box to the appropriate terminals – see Table 7.2.
Connect the milliammeter to the retransmission output terminals – see Fig. 3.5 or 3.6.
c) Switch on the supply and allow ten minutes for the circuits to stabilize.
d) Select the
Factory Settings Page
and carry out the procedure in Section 7.7.
Table 7.2 Transmitter Terminal Functions