Resistivity Unit (Hi 98194, Hi 98195 Only); Seawater Sigma Unit (Hi 98194, Hi 98195 Only); Absolute Ec Resolution Unit (Hi 98194, Hi 98195 Only); Tds Resolution Unit (Hi 98194, Hi 98195 Only) - Hanna Instruments HI 98194 Instruction Manual

6.2.5 Resistivity Unit (HI 98194, HI 98195 only)

The user can select resistivity from one of the
following measurement units: Ω·cm, kΩ·cm or
MΩ·cm. Resistivity is calculated from the conductivity
measurement. The default unit is MΩ·cm.

6.2.6 Seawater Sigma Unit (HI 98194, HI 98195 only)

This parameter is used for seawater analysis. It is
calculated from the conductivity measurement and
depends on water pressure, temperature and salinity.
The default value is σ
.
t
Users can select the reference temperature: σ
and σ
(i.e. current temperature, 0 °C or 15 °C).
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6.2.7 EC Resolution (HI 98194, HI 98195 only)
The user can configure the conductivity resolution
with one of the following options:
Auto: the meter automatically chooses the range
to optimize the measurement. Readings can be in
µS/cm or mS/cm.
Auto mS/cm: the meter automatically chooses
the range to optimize the measurement, readings will be in mS/cm only.
1µS/cm, 0.001 mS/cm, 0.01mS/cm, 0.1mS/cm or 1mS/cm: the meter will not
autorange, the measurement will be displayed with the selected resolution. The
default value is Auto.
6.2.8 Absolute EC Resolution (HI 98194, HI 98195 only)
Absolute conductivity displays the conductivity without temperature compensation.
See 6.2.8 EC resolution for resolution details.
Note A small letter "A" added to the µS/cm or mS/cm unit refers to an absolute
conductivity value (i.e. a conductivity reading with no temperature
compensation).
6.2.9 TDS Resolution (HI 98194, HI 98195 only)
The user can configure the TDS resolution with one of the following options:
Auto: the meter automatically chooses the range to optimize the measurement,
readings can be in ppt or ppm.
Auto ppt: the meter automatically chooses the range to optimize the measurement,
readings will be in ppt only.
1 ppm, 0.001 ppt, 0.01 ppt, 0.1 ppt or 1 ppt: the meter will display the
measurement with selected resolution. The default value is Auto.
, σ
t 0
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6.3 PARAMETER COEFFICIENTS

6.3.1 EC Reference Temperature (HI 98194,
HI 98195 only)
This value is used for temperature compensated
conductivity. All EC measurements will be referenced
to the conductivity of a sample at this temperature.
Press the softkey to select the desired option; 20 °C or at 25 °C. The default value
is 25 °C.
6.3.2 EC Temperature Coefficient (HI 98194,
HI 98195 only)
The temperature coefficient Beta (β) is defined by
the following equation (using 25 °C as an example):
EC =EC /(1+β(T -25))
25 x x
Beta is a function of the solution being measured. For freshwater samples Beta is
approximately 1.90%/°C. If the actual temperature coefficient of your sample is
known, press Modify to enter the value. To confirm press Accept. The value can
be within 0.00 and 6.00%/°C. The default value
is 1.90%/°C.

6.3.3 TDS Factor (HI 98194, HI 98195 only)

TDS stands for total dissolved solids, and it is a
calculated value based on the conductivity of the
solution (TDS = factor x EC ). The TDS conversion factor can be set from 0.00 to
25
1.00. A typical TDS factor for strong ionic solutions is 0.5, while for weak ionic
solutions (e.g. fertilizers) is 0.7. Press Modify to enter the value, press Accept to
confirm. The default value is 0.50.

6.4 Averaging

Averaging is a software filter to minimize sensor
noise and provide more stable readings.
Averaging is particularly useful to get a
representative reading of the "average" value from
flowing water. Averaging will affect all
measurements. This value should be kept low if
you want a fast response. Press Modify to select
the desired number of samples to average. This
value can be set from 1 to 20 samples. The
default value is 1.
Note Each reading takes 1 second, so when logging the first sample will be
delayed by a few seconds if averaging is used.
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