Page 39 - EngineerIT December 2022

NEWS DIGEST

MULTIPARAMETER PROBE AND LOGGER FOR

WATER LEVEL MONITORING

he supply of clean drinking water
and guaranteeing its quality and
Tquantity is becoming a more
acute, important and costly issue. To
record parameters from a body of
water, in addition to the most measured
parameters such as determining the water
level and temperature, other measured
variables must also be determined, for
example, conductivity. Conductivity is a
good indicator of water cleanliness and
an important parameter in the supply of
drinking water.
Instrotech, the local supplier of Keller
has a CTD multiparameter probe and
logger that measures and monitors the
quality and quantity of drinking water.
flow between the electrodes immersed in a medium is measured; the greater the current
‘CTD’ is the acronym for conductivity, flow, the higher the conductivity. Conductivity sensors for water bodies measure from a
temperature and depth and is determined few micro-siemens per cm (µS/cm) to about 200 milli-siemens per cm (mS/cm).
by the following sensor elements:
• Conductivity sensor (Conductivity) Some example values:
• Temperature sensor PT1000 • Distilled water 0,05 µS/cm to 1 µS/cm
(Temperature) • Drinking water 300 µS/cm to 800 µS/cm
• Pressure sensor (Depth) • Seawater approximately 50 mS/cm

Since these parameters are directly Temperature
dependent on each other, Keller Temperature changes in a substance also mean a change in conductivity. This means
incorporates three sensors into one device that at higher temperatures the number of dissolved ions and their mobility increases
to provide compensated and thus highly significantly, for example, the conductivity increases.
accurate measured values. The temperature can be read out as an independent measuring value, but Keller
uses it to compensate for the other parameters. The PT1000 temperature sensor is
Conductivity located directly next to the titanium electrodes, so the temperature and conductivity are
Some media or substances, such as water, measured at the same point.
can transmit heat, sound, or electricity.
The more dissolved ions (chlorides, Depth
sulphates, or carbonates) there are in The water depth is determined by the difference between the surface and the immersion
a substance, the higher its electrical depth. In measurement technology, one refers to the so-called water column. For example,
conductivity. a water column of 10 m corresponds to a pressure difference of approximately 1 bar.
Because of high numbers of dissolved
ions, sea or salt water has a conductivity The application dictates which of two different measuring methods is used:
many times higher than conventional • Absolute pressure (related to vacuum)
drinking or fresh water. Carefully distilled • Relative pressure (related to ambient pressure).
water, on the other hand, contains very
few to zero dissolved ions, which prevents Keller’s multiparameter probe series 36XiW-CTD and the multiparameter loggers’ series
the transportation of electrical current in DCX-22-CTD / DCX-22AA-CTD combine all the above-mentioned measurements in one
the water. device.
Conductivity is determined by six
titanium electrodes. The electrical current For more information click here

EngineerIT | December 2022 | 39