Hanna Instruments HI 720 Instruction Manual page 17

If the item P .14 has been set to "222", no expiration date check will be done.
( 2 6 ) This item is particularly useful in noisy environment, to filter measurement
spikes and avoid undesired activations of the on/off control contacts. The relay
energizes and de-energizes only if the corresponding threshold is overridden for
more than the configured contact action delay (see below graph: "dly" is the
contact action delay; relays are energized and de-energized at times t
( 2 7 ) The alarm mask time specifies for how long the conductivity/concentra-
tion/temperature value must remain outside the alarm thresholds before an alarm
is actually generated. Note that the conductivity/concentration/temperature value
must return within the alarm thresholds and remain stable for the same time,
before the device can close the alarm.
( 2 8 ) The linear temperature compensation is performed according to the
following formula:
Compensated conductivity = Actual conductivity / [1+ (T-Tref)/100]
where T is the measured temperature
and Tref is the reference temperature (20 or 25°C).
The temperature coefficient must be manually adjusted by the user when chang-
ing the reference temperature. If
ficient with Tref=20°C must be calculated as follows:
For example, if =1.90 %/°C, then
For the NaCl temperature compensation algorithm, the compensation for-
mula is the same as for the linear method, but with depending on the tempera-
ture value according to the IEC 746-3 BII table (also see the "Temperature Com-
pensation" section).
( 2 9 ) The temperature coefficient can always be viewed and modified, but the
set value is used only if the linear compensation method is selected.
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is the coefficient with Tref=25°C, the
= / (1 - /20).
= 2.10 %/°C.
( 3 0 ) This parameter set the number of latest measurements used to calculate
an average value. The average is calculated both for conductivity/concentration
and temperature. The averaged conductivity/concentration value is then used
both for displaying and control.
( 3 1 ) When the concentration unit is changed, all items from C.00 to C.34 and
+dly). from O.12 to O.15 are reset to the default values.
n
( 3 2 ) The degree Fahrenheit unit is used only for displaying the temperature
while in normal measurement mode.
( 3 3 ) The default values for the temperature compensation table are:
Couple
10
( 3 4 ) When setting/reading the concentration tables via RS485, use the setup
item d.06 to specify the edit/view table (values are 1, 2, 3, 4).
( 3 5 ) The HI 504902 modem module is certified by Telecom to work in the
following countries: Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile,
China, Cyprus, Czech Republic, Denmark, Finland, France,
coef-
Germany, Greece, Hong Kong, Hungary, Iceland, India, Indonesia, Ireland, Is-
rael, Italy, Japan, Korea, Liechtenstein, Luxembourg, Malaysia, Mexico, Nether-
lands, New Zeland, Norway, Philippines, Poland, Portugal, Russia, Singapore,
Slovak Republic, South Africa, Spain, Sweden, Switzerland, Taiwan, Turkey, United
Kingdom, United States.
If your country is not present in the list, please contact your Hanna dealer.
If the country code is shorter than 3 digits, fill the code with zeros in front.
( 3 6 ) There is a fixed 0.3°C hysteresis for the temperature levels.
Actual Conductivity
1 500 μS/cm
2 600 μS/cm
3 700 μS/cm
4 800 μS/cm
5 900 μS/cm
6 1000 μS/cm
7 1100 μS/cm
8 1200 μS/cm
9 1300 μS/cm
1400 μS/cm
Temperature
0.0 °C
5.0 °C
10.0 °C
15.0 °C
20.0 °C
25.0 °C
30.0 °C
35.0 °C
40.0 °C
45.0 °C
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