General Description & Intended Use
4
2. GENERAL DESCRIPTION & INTENDED USE
Testing and monitoring salinity in saltwater aquariums is an ongoing task.
The
HI981520
is a vertical‑mount unit that monitors
and displays the
conductivity
(measured with attached
probe) and the
pH
level
(replaceable pH electrode).
Each parameter can be configured for high/low operating mode and the results are displayed on a large, easy
to read LCD.
The system can be calibrated at one or two points for pH and at one point for conductivity.
Seawater salinity is expressed in either parts per thousand (ppt), Practical Salinity Units (PSU), or Specific
Gravity (S.G.).
ppt
Measurements expressed in ppt are based on the Natural Seawater Scale that extends from 0.00 to 80.00 g/L
and covers 10 to 31 °C temperature range. It determines the salinity based upon a conductivity ratio of sample
to standard seawater at 15 °C and an approximate salinity value of 35 in seawater.
PSU
The practical salinity of seawater relates the ratio of electrical conductivity of a normal seawater sample at
15 °C and 1 atmosphere to a potassium chloride solution (KCl) with a mass of 32.4356 g/Kg water at the same
temperature and pressure. Under these conditions the ratio is equal to 1 and S=35. The practical salinity scale
may be applied to values 0 through 42.00 psu at temperatures between 0 to 35 °C.
Specific Gravity (S.G.)
Specific Gravity, or relative density, is expressed as the ratio of the density of seawater, at a specific temperature,
relative to the density of the same volume of pure water at a specific temperature.
The probes are
secured with suction cups
to the back of an aquarium (tank) and are suited for continuous
measurement of conductivity and associated parameters required in applications such as seawater, saltwater
aquariums, or aquaculture.
The distance between monitored sample and monitor unit extends to
2 m
(6.6’)
probes cable
length.
The system is simple to install (self‑adhesive or screw mount) and easy to setup and use.
Main Features
• Two Alarm operating modes (High/Low Value) for each supported parameter
• High/Low Alarm generated when measured value exceeds or drops below configured parameter High/Low
Value
• Acoustic signal generated each time an alarm is triggered
• The EC probe contains an integral temperature sensor that simplifies installation
• All readings are compensated for variations in temperature
• Temperature is displayed in °C or °F along with pH and EC readings
• Easy to read LCD display
