Hanna Instruments HI 23 - Manual (Page 4)

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FUNCTIONAL DESCRIPTION
1. Liquid Crystal Display
2. CAL DATA key
last calibration data viewing (enters and exits)
3. LCD key exits from setup and reverts back to normal mode (in idle
or control phases with the measurement on the display).
During EC/TDS calibration, it alternates EC/TDS buffer
value and current cell constant on the display. In HI 24
series, it switches between EC and TDS reading
4. CAL key initiates and exits calibration mode
5. SETUP key enters setup mode
6. key moves to the next digit/letter (circular solution) when se-
lecting a parameter. Same as key during last calibration
data viewing mode
7. key increases the blinking digit/letter by one when selecting a
parameter. Advances forward while in last calibration
data viewing mode. Increases the temperature setting
when temperature probe is not inserted
8. CFM key confirms current choice (and skips to the next item)
9. key decreases the blinking digit/letter by one when selecting
a parameter. Reverts backward while in last calibration
data viewing mode. Decreases the temperature setting
when temperature probe is not inserted
10. LEDs
• Calibration: 2 points with Hanna EC and TDS calibration
solutions.
• Four different EC working ranges (0 to 199.9 µ S; 0 to
1999 µ S; 0 to 19.99mS; 0 to 199.9mS).
• Four different TDS working ranges (0 to 100.0ppm; 0 to
1000ppm; 0 to 10.00ppt; 0 to 100.0ppt) for HI 24 series.
• Possibility to switch to TDS measurements with conversion
factor from 0.00 to 1.00 (HI 24 series).
• Temperature compensation of the HANNA standard solu-
tions.
• Temperature compensation of the EC and TDS reading with
temperature coefficient ß selectable from 0 to 10%/°C.
• Use of a 3-wire Pt 100 temperature sensor to compensate
for the cable resistance and have a precise automatic tem-
perature compensation of the measurements in long dis-
tance applications.
• Manual temperature setting when the temperature probe is
not inserted or the temperature exceeds the upper range.
• Last calibration data internally recorded (nonvolatile EE-
PROM memory): calibration date and time, cell constant,
calibration solution values.
• Input: 4-ring EC/TDS probe with cell constant 2.0 ± 10%,
or 4-20mA analog input from a transmitter.
• Analog output (HI 23xy1 and HI 24xy1)
- isolated 0-1 mA, 10 K Ω maximum load (optional);
- isolated 0-20 mA, 750 Ω maximum load (optional);
- isolated 4-20 mA, 750 Ω maximum load (optional);
- isolated 0-5 VDC, 1 K Ω minimum load (optional);
- isolated 1-5 VDC, 1 K Ω minimum load (optional);
- isolated 0-10 VDC, 1 K Ω minimum load (optional).
• Real time clock.
• Serial comunication via RS485 with the possibilities to set
the working parameters and to read the displayed data (HI
23xy2 and HI 24xy2).
• Calibration and Setup procedures allowed only through
an unlock password.