The Model 499ATrDO sensor is a membrane-covered amperometric sensor for the continuous determination of ppb-level dissolved oxygen in water. The primary application is the measurement of dissolved oxygen in steam condensate and boiler feedwater.

The sensor response is highly linear. Following calibration in air (equivalent to about 8500 ppb dissolved oxygen), the error for concentrations below 20 ppb is ±1 ppb.

Comedown time is rapid. When first placed in service, the sensor is accurate at the 1 ppb level within five hours. Following air calibration, the stabilization time is about 20 minutes. Unlike competing sensors that use an oxygen-scavenging electrode to remove internal oxygen, the 499A TrDO relies on a self-depleting design. The result is a more robust, reliable sensor.

SENSOR SPECIFICATIONS
Pressure: 0 to 65 psig (101 to 549 kPa abs)
Temperature:
   Operating: 5 to 45°C (41 to 113°F)
   Storage: 0 to 60°C (32 to 140°F)
Wetted Materials: Noryl, Viton, Teflon (PTFE), silicone
Cathode: gold (not normally wetted)
Process Connection: 1" MNPT
Electrolyte Volume: 25 mL (approx)
Electrolyte Life: 4 to 6 months (approx)
Sensor Life: 2 years (approx)
Temperature Sensor: Pt 100 RTD (Type B)
Cable Length: (std integral) 25 ft (7.6m); (max) 300 ft (91 m)
Range: 0.1 ppb to 20 ppm
Accuracy at 25°C following air calibration:
   <20 ppb ±1 ppb
   >20 ppb ±5% of readingDrift: <4% over 60 days
Sample Flow: Response increases less than 2% when flow changes from 100 to 400 mL/min. At 50 mL/min, sensor response is about 90% of value at 100 mL/min.
Response Time at 25°C: <20 sec to 90% of final reading at 25°C (0 to 200 ppb oxygen)
Comedown Time to 1 ppb:
   New sensor: <5 hours
   Following membrane change: <1 hour
   Following air calibration: <1 hour
Shelf Life: 3 months. If the shelf life has been exceeded, the sensor can still be used. The comedown time will be longer.
Weight/Shipping Weight: 1 lb/3 lb (0.5 kg/1.5 kg)

FLOW CELL SPECIFICATIONS
LOW FLOW CELL PN 24091-00
Wetted Parts: polycarbonate, 316 stainless steel, Buna N
Process Connection: 1/4" OD tubing compression fitting or 1/4" FNPT
Maximum Pressure: 65 psig (549 kPa abs)
Maximum Temperature: 122°F ( 50°C)
Weight/Shipping Weight: 1 lb/2 lb (0.5 kg/1.0 kg)

ANALYZER COMPATIBILITY
Use the Model 499A TrDO with the 1056, 54eA, 5081-A, or Xmt-A analyzer.
The sensor is not compatible with the 1054ADO, 1054BDO, and 1181DO.