COVER STORY
INSTRUMENT –
12 Water Quality Parameters The HI98494 Multiparameter Bluetooth Portable pH/EC/OPDO Meter is a product of Hanna Instruments’ philosophy to provide people with an easyto-use, common-sense approach to their testing needs – at an affordable price.
D
esigned to withstand harsh environmental conditions and ideal for field measurements, the HI98494 instrument is a waterproof combination of a portable, rugged meter and a digital probe.
MEASURED 1.
pH
The measure of how acidic/basic water is
2.
ORP
Oxygen reduction potential
3.
Conductivity
The water’s capability to pass electrical flow
4.
Dissolved oxygen
The amount of oxygen in water
5.
Temperature
In °C
CALCULATED 6.
pH-mV
Probe measures a potential difference between the pH sample and a reference measured in units of millivolts
7.
Absolute conductivity
A conductivity measurement without temperature compensation
8.
Resistivity
The ability the water has to resist an electrical current, which is determined by the concentration of dissolved salts in the water
9.
Total dissolved salts
Describes the inorganic salts and small amounts of organic matter present
10.
Salinity
The saltiness or amount of salt dissolved in a body of water
11.
Seawater sigma
The density at a given temperature
12.
DO concentration
The concentration of dissolved oxygen
TABLE 1 The HI98494 monitors 12 water quality parameters – of which five are measured and seven calculated. Each parameter is fully configurable
4
MAR /APR 2021
The HI98494 allows for an easy one-point calibration of pH and EC sensors
Digital probe
The microprocessor-based intelligent probe (also called the HI7698494 sensor) comprises three sensors that are field replaceable, with auto-sensor direction and colour-coded caps: 1) Red – for pH and ORP measurements. 2) Blue – conductivity and all associated parameters. 3) Green – does DO measurements over long periods of time without the need for frequent calibration. The sensor also has a built-in temperature sensor and a removable protective shield. It is designed for a variety of water quality measurements both in situ and in active deployments in urban or natural waters. HI98494 has various probe cable lengths (4 m, 10 m, 20 m and 40 m) and the probe may be installed in a horizontal bank (fixed installation) or a vertical suspension (at a maximum depth of 20 m). Unlike probes that require a cable support for active deployments, the
