Green
OK LED
Yellow
Z LED
Yellow
S LED
Red
F LED
Fault diagnostic
OFF
OFF
OFF
ON
Input power
voltage fault.
ON
OFF
OFF
ON
System 4 – 20 mA
monitor fault.
OFF
ON
OFF
ON
Source current
fault.
ON
ON
OFF
ON
Maths fault (or un-
derrange fault).
OFF
OFF
ON
ON
Spare fault
designator.
ON
OFF
ON
ON
Spare fault
designator.
OFF
ON
ON
ON
A/D, RAM, ROM
fault.
ON
ON
ON
ON
EEPROM fault.
CALIBRATION
The TX600 transmitter board is calibrated to provide a linear 4 –
20 mA output for an IR600 Series sensor seeing gas
concentrations from zero to full span.
A TX600 transmitter
board and IR600 Series sensor are normally supplied as a
pair and are calibrated for the default full span gas
concentration of the sensor.
Should a different calibration
be required, then re-calibration may be performed using a
DX600 display board and a supply of calibration gas.
To re-calibrate, perform the following operations:
i)
Set up the TX600 transmitter board and sensor:
a) Connect a 100 W load resistor across the current output
(I+) and 0 V terminals of connector PL1.
b) Connect the power supply leads to the power input
(V+) and 0 V terminals of PL1.
c) Plug the IR600 connector into header PL3.
d) Plug the DX600 display board into socket PL2.
e) Apply nitrogen to the sensor at 1 litre per minute (e.g.
using a Quick Calibration Hood, e2v product number
DPP546618DA).
f) Preset the power input to 24 V (with a current limit of
250 mA) then switch the power on.
ii) Perform the Zero Calibration Test:
a) Ensure the green OK LED is flashing, then press the CAL
button. The yellow Z LED will illuminate; this indicates
that the sensor is in set zero mode. Press the UP and
DOWN buttons on the DX600 Display board as required
to make the reading show "000". When this reading is
stable, press the CAL button on the DX600 board. This
stores the sensor zero in the TX600 memory. Check that
the yellow Z LED is extinguished, the yellow S LED
illuminates and the green OK LED remains flashing.
iii) Perform the Span Calibration Test:
a) Apply the calibration gas to the IR600 sensor head at a
flow rate of 1 litre per minute.
b) Press the UP and DOWN buttons on the DX600 board as
required to make the display show the percentage of the
appropriate full scale value, dependent upon the IR600
sensor type, set by the sensor select switches SW1 on
the TX600 Transmitter Board (see A1A-TX600 data
sheet). Once the reading is stable, press the CAL button
on the DX600 board. This stores the span value in the
TX600 memory. Check that both the yellow Z LED and
the yellow S LED illuminate and that the green OK LED
remains flashing.
iv) Set the sensitivity of the sensor:
As a default, the TX600 is calibrated to read full scale on
the DX600 display when the sensor sees full concentra-
tion span gas. However, the TX600 may be set up to
read full scale for a lesser concentration:
a) Perform calibration for zero to full span gas concentra-
tion (as per ii and iii above). Both yellow LEDs should be
lit and the green OK LED should be flashing at the end of
this procedure.
b) Apply the required full scale gas concentration to the
sensor at a flow rate of 1 litre per minute and wait for the
reading to become stable.
c) Press the UP and DOWN buttons on the DX600 board as
required to make the display show full scale. When the
reading is stable, press the CAL button on the DX600
display board to store the sensitivity value in memory
and exit the calibration cycle. Check that both the yellow
LEDs extinguish and that only the green OK LED remains
flashing.
Example:
IR601 Series sensor with default calibration 0 – 2%
vol. CO
2
. To set up for 0 – 1% vol. CO
2
:
a) Perform calibration for 0 – 2% vol CO
2
(as per ii and iii
above).
b) Apply 1% vol. CO
2
and wait for the reading to remain
constant at 50% full scale.
c) Adjust sensitivity to 100% full scale then press the CAL
button to store the sensitivity value in memory and exit the
calibration cycle.
Note that for the default calibration, the sensitivity value is the
same as the full scale span value.
Note:
The DX600 displays the output from the TX600 and is
normally calibrated to display zero to full scale readings of 1.00,
2.00, 5.00, 100, 200 or 500 (see below) for TX600 outputs of 4 –
20 mA at terminal (I+) or 0.4 – 2.0 V at terminal (V+) when a
100
O
resistor is placed across the (I+) and 0 V terminals. The
full scale reading is set by the configuration of DX600 links LK1,
LK2,LK3 and LK4 as follows:
Full Scale
Reading
LK1
LK2
LK3
LK4
1.00
Made
Made
Unmade
Unmade
2.00
Made
Unmade
Made
Unmade
5.00
Made
Unmade
Unmade
Made
100
Unmade
Made
Unmade
Unmade
200
Unmade
Unmade
Made
Unmade
500
Unmade
Unmade
Unmade
Made
#
e2v technologies
DX600, page 3