Hanna Instruments HI 2214, Instruction Manual, Page: 16 / 24

16
RELATIVE mV CALIBRATION
• Press CAL when the instrument is in RELATIVE mV measurement
mode. The “
mV
” and “ ” tags will be displayed. Absolute mV is
displayed on the primary LCD and “ AbS ” message is displayed on the
secondary LCD.
• When the absolute reading is stable and in measurement range, the
instrument asks for confirmation.
• If the reading is out of range, “ WRONG ” tag will be displayed.
• Press CFM to confirm the absolute value. The instrument will display
“
0.0 mV
“ on the primary LCD and “
rEL
” message on the secondary
LCD. In this moment the relative mV offset is equal to absolute mV
reading.
• Use the ARROW keys if you want to change the displayed relative
mV value.
• Press CFM to confirm the relative mV value. The relative mV
offset is displayed on the primary LCD. The instrument returns to
measurement mode.
Note: The relative mV value can be changed only inside the relative mV
offset window (± 2000 mV).
33
CHR xx Change the instrument’s range according to the parameter‘s
value (xx):
• xx=00 pH range/0.001 resolution
• xx=01 pH range/0.01 resolution
• xx=02 pH range/0.1 resolution
• xx=03 mV range
• xx=04 Relative mV range
The instrument will answer for these commands with:
<STX> <answer
>
<ETX>
where: <STX> is 02 ASCII code character (start of text)
<ETX> is 03 ASCII code character (end of text)
<answer>:
<ACK> is 06 ASCII code character (recognized command)
<NAK> is 21 ASCII code character (unrecognized command)
<CAN> is 24 ASCII code character (corrupted command)
COMMANDS REQUIRING AN ANSWER
The instrument will answer for these commands with:
<STX> <answer> <checksum> <ETX>
where the checksum is the bytes sum of the answer string sent as 2 ASCII
characters.
All the answer messages are with ASCII characters.
RAS Causes the instrument to send a complete set of readings in
according to the current range:
• pH, temperature and mV readings on pH range.
• Rel mV, absolute mV and temperature readings
on Relative mV range.
The answer string contains:
• Meter mode (2 chars):
• 00 - pH range (0.001 resolution)
• 01 - pH range (0.01 resolution)
• 02 - pH range (0.1 resolution)
• 03 - mV range
• 04 - Rel mV range
• Meter status (2 chars of status byte): represents an
8 bit hexadecimal encoding.
• 0x10 - temperature probe is connected
• 0x01 - new GLP data available
• 0x02 - new SETUP parameter