Yokogawa DO402 Dissolved Oxygen Analyzer - Manual (Page 17)

IM 12J05D02-01E
Specification 2-1
2-1. General
A. Input specifications
: The DO402G Dissolved Oxygen
converter measures the cur-
rent, that is generated by the
Dissolved Oxygen sensor. The
flexibility of the input circuit
allows the use of many com-
mercially available sensors,
whether they are of the Galvanic
type (driving voltage generated
internally) or Polarographic type
(driving voltage supplied by con-
verter)
The input range varies from
0.0 nA up to 500 nA for optical,
polarographic sensors and 0.0
to 50 µA for galvanic sensors.
Temperature measurement for
automatic temperature compen
sation utilizes Pt100, PT1000
RTD elements or PB36 as used
in DOX8, DO30 and DO70G
sensors, as well as the 22 k
NTC as used by the Hamilton
Oxyferm.
B. Measurement ranges
- DO : 0- 50 mg/l (ppm)
- Temperature : 0- 50 ºC (32- 122 ºF)
C. Span
- DO concentration
: minimum: 1 mg/l (ppm)
maximum: 50 mg/l (ppm)
- % saturation : minimum: 10 %
maximum: 300 %
- Temperature : minimum: 25 ºC (77 ºF)
maximum: 50 ºC (122 ºF)
D. Output Signals
: Two isolated outputs of 0/4- 20
mA DC with common nega-
tive. Maximum load 600 Ohm.
Auxiliary output can be chosen
from Temperature, DO, PI con-
trol, table, burn up (22 mA) or
burn down (0 or 3.5 mA) to sig-
nal failure
E. Temperature compensation
: 0- 50 ºC
Sensor types: Pt100 or Pt1000
RTD; PB36 (Yokogawa compat
ible);
22 k NTC (Ingold compatible)
Automatic or Manual tempera-
ture compensation
F. Calibration
: Semi-automatic calibration with
automatic compensation for
influence of barometric pressure
and altitude on partial pressure
of oxygen in air (or solubility
of oxygen in water). Automatic
compensation for influence of
salinity of water on solubility of
oxygen in water is programma-
ble.
The correction for pressure,
salinity and temperature meets
ISO 5814
Possible calibration routines are:
- Slope (span) calibration in
ambient air. The calibration
table is based on 70 % RH and
is determined empirically.
- Slope (span) calibration in
water, saturated with air:
according ISO 5814
- Zero calibration (normally inac-
tive)
G. Serial Communication
: Bi-directional according to the
EIA-485 standard using HART
protocol and PC402 software.
H. Logbook
: Software record of important
events and diagnostic data.
Available through RS485, with
key diagnostic information avail-
able in the display.
I. Display
: Custom liquid crystal display,
with a main display of 3
1
/
2
digits
12.5 mm high. Message display
of 6 alpha numeric characters, 7
mm high.
2. DO402G SPECIFICATIONS