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| Range | Dissolved Oxygen | 0.00 to 90.00 ppm; 0.0 to 600.0 % saturation |
| Barometric Pressure | 450 to 850 mmHg; 560 to 1133 mBar | |
| Temperature | -20.0 to 120.0°C; -4.0 to 248°F; 253.1 to 393.1 K | |
| Resolution | Dissolved Oxygen | 0.01 ppm; 0.1% saturation |
| Barometric Pressure | 1 mm Hg | |
| Temperature | 0.1°C/°F/K | |
| Accuracy | Dissolved Oxygen | ±1.5% of reading ±1 digit |
| Barometric Pressure | ±3 mm Hg + 1 least significant digit | |
| Measurement Modes | direct DO; BOD (biochemical oxygen demand); OUR (oxygen uptake rate); SOUR (specific oxygen uptake rate) | |
| Calibration | Dissolved Oxygen | automatic/user standard, one or two points |
| Barometric Pressure | single point | |
| Temperature Compensation | 0.0 to 50.0°C; 32.0 to 122.0°F; 237.1 to 323.1 K | |
| Salinity Compensation | 0 to 45 g/L (ppt) | |
| Probe | thin body, polarographic dissolved oxygen probe with internal temperature sensor and 1 m (3.3’) cable (included) | |
| Logging | Record Samples | up to 100 lots; 10,000 samples/lot for automatic logging; 5000 samples/lot for manual logging |
| Logging Interval | from one second and up | |
| Type | manual, automatic | |
| GLP Features | yes (last calibration data, calibration info) | |
| Alarm (DO, BOD, OUR, SOUR) | inside and outside limits | |
| PC Connection | opto-isolated USB and RS232 | |
| Display | graphic color LCD with on-screen help, graphing, language selection and custom configuration | |
| Power Supply | 12 VDC adapter (included) | |
| Dimensions | 160 x 231 x 94 mm (6.3 x 9.1 x 3.7”) | |
| Weight | 1.2 Kg (2.6 lbs.) |
HI 4421 is a research grade dissolved oxygen bench meter with extensive capabilities in measuring DO as BOD (Biological Oxygen Demand), OUR (Oxygen Uptake Rate), SOUR (Specific Oxygen Uptake Rate), atmospheric pressure and temperature.
DO measurements can be performed in ppm (mg/L) range or in % and feature automatic or manual temperature and atmospheric pressure compensation and manual salinity compensation.
Automatic and manual calibration of DO can be performed in one or two points using standard or user defined standards. Users can set the reading stability criteria; three modes are available: Fast, Medium and Accurate. Direct/autohold auomatically holds the reading on display when measurement stability is reached. In direct reading mode, the user interface can be set to basic with or without GLP, graphic or logging information.
These instruments offer multi-language support and contextual help is available through a dedicated Help key. Clear tutorial messages and directions are available on-screen to quickly and easily guide users through all measurement and calibration procedures to ensure measurements and procedures are performed properly.
The BOD, OUR and SOUR methods are supported with a dedicated tutorial and step by step indication in order to assure a full and correct reading of DO using this specific measuring method.
The DO probe is using the polarographic principal of measurement and has a built-in temperature sensor.
Up to 10 profiles can be saved and recalled eliminating the need to reconfigure each time when a different electrode is used. User definable configurations can include reading mode: direct or BOD, OUR, and SOUR, measurement units, temperature units, stability criteria, and temperature, atmospheric pressure and salinity compensation.
Three selectable logging modes are available: Automatic, Manual and AutoHold logging. Up to 100 logging lots can be stored for automatic or manual modes. Automatic logging features a selectable area and sampling period while GLP information includes complete data about user calibration of each parameter and identification information for the instrument, user, and company. Data can be transferred to a PC via the opto-isolated PC interface via the RS232 or USB ports and HI 92000 software (optional).
Order Information:
HI 4421-01 (115V) and HI 4421-02 (230V) is supplied with HI 76408 DO probe, HI 76404N electrode holder, HI 7041S electrolyte solution (30 mL), HI 76407A membrane caps (2), 12 VDC adapter and instruction manual.
