| Principle
of measurement |
Membrane covered polarographic
oxygen probe, self polarizing galvanic cell |
| Oxygen Probe |
|
|
| Output signal |
Approximately 5mV per mg/l,
2mV per % vol/vol |
| Output impedance |
Approximately 1K ohm |
| Oxygen Probe Model 420 |
|
|
| Process signal |
4-20 mA |
|
| Loop power supply |
15-35V DC, typically 24V
DC, |
| Allowable loop resistance |
Up to 1000 ohms. |
|
| Probe Options |
Type I |
Type II |
| Range: Dissolved Oxygen |
0-40mg/l, 0-400% Sat |
0-15 mg/l, 0-150% |
| Range: Gaseous Oxygen |
0-100% Vol / Vol |
0-35% Vol / Vol |
| Temperature compensation |
Automatic from 4° -
40°C (40° - 104°F) |
| Accuracy |
Better than
±2% of reading when calibration temperature equals
measuring temperature ±5 C. Zero drift less than
1 mg/l |
| Repeatability: mg/l |
Better than ±0.2
mg/l |
| Repeatability: %Vol |
Better than ±0.5%
vol/vol when barometric pressure unchanged |
| Response time: mg/l |
1 minute for 90% of 100%
step change at constant temperature |
| Response time: %Vol |
10 secs. for 90% of 100%
step change at constant temperature |
| Construction Materials
|
Type I |
Type II |
| Probe electrodes |
Silver cathode / Zinc anode |
Silver cathode / Lead anode |
| Probe electrolyte |
NaCl |
Na2CO3 |
| Probe body |
POM (poly-oxy-methylene) |
| O-rings |
Viton |
| Membrane |
50 µm (2 mil) teflon |
| Dimensions & Weight |
|
| Oxygen
Probe |
58mm diameter
x 59mm high (2 1/4 in dia. x 2 1/2 in)
350g (3/4 lb) including standard 3m (10ft) cable
length |
| Oxygen
Probe Model 420 |
58 mm diameter
x 88 mm high (2 1/4 in dia. x 3 1/2 in)
350 g (1 1/2lb) including standard 3m (10ft) cable
length |
| Cable |
2-conductor,
0.75 mm2 (16 gauge), standard length 3 m (10 ft), other
lengths available upon request |
| Operating Conditions |
|
|
| Temperature |
0° to 40°C (32°
to 104°F) |
| Pressure |
Maximum 10 atmospheres
(147 psig.) |
| Minimum submersion |
depth 60mm (2 1/2
in) |
| Minimum water flow |
2.5cm/s (1in/sec) across
membrane |
| Calibration |
In air, or air saturated water (use of EasyCal calibrator optional). |
