User manual HANNA INSTRUMENTS BL 932700

[. . . ] Damages due to accident, misuse, tampering or lack of prescribed maintenance are not covered. If service is required, contact the dealer from whom you purchased the instrument. If under warranty, report the model number, date of purchase, serial number and the nature of the failure. [. . . ] Two models are available: · BL 932700-0 powered at 12 Vdc · BL 932700-1 powered at 115 or 230 Vac ASSEMBLING VIEW FUNCTIONAL DESCRIPTION Front panel Rear panel OPERATIONS REAR PANEL CONNECTIONS Terminals #1, #2 and #3: Electrode · Connect an ORP electrode to the meter BNC plug (#1). · To benefit from the differential input, connect the proper electrode wire (if available) or a cable with a potential matching pin (grounding bar) to the relevant terminal (#3) on the rear panel. Note: When the Matching Pin can not be immersed together with the electrode in the solution, disable the differential input by shorting terminals #3 (Matching Pin) and #2 (Electrode Reference) with a jumper wire. Terminals #4: Dosing selection · For Rdx dosage, leave the circuit open. · For Oxd dosage, short the terminals with a jumper wire. Terminals #5: 4-20 mA Output · These output terminals are used for connecting a recorder. The output is from 4 to 20 mA and is proportional to the measured ORP value. Terminals #6: Power Supply · Model BL932700-0: connect the 2 wires of a 12 Vdc power adapter to the terminals +12 Vdc and GND. · Model BL932700-1: connect a 3-wire power cable to the terminals while paying attention to the correct earth (PE), line (L) and neutral (N1 for 115 V or N2 for 230 V) contacts. Terminals #7: Dosing Contact · This contact drives the dosing system, accordingly to the selected setpoint and dosing direction: · if "Rdx" dosage is set, the relay is ON and dosing activated if measured value is higher than setpoint; · if "Oxd" dosage is set, the relay is ON and dosing activated if measured value is lower than setpoint. Note: The setpoint has a typical hysteresis value comparable to the meter accuracy. Terminals #8: External Disabling Contact · This is a normally open contact and can be used for example for connecting a level controller. · When the contact is closed, any dosing action stops, the LED indicator on the front panel will blink Red and the LCD will show the "HALT" warning message. Note: If the OFF/Auto/ON switch is in ON position, the dosing action will not stop, even if the external disablig contact is closed. Dosage will proceed, the LED indicator will lit Orange/Yellow and the LCD will show the "HALT" warning message. Overtime system: jumper (#9) and trimmer (#10) · This system allows the user to set a maximum dosing period, by adjusting the rear trimmer from 5 (min) to approx. · When the set time is exceeded, any dosing action stops, the LED indicator on the front panel will blink Red and the LCD will show the "TIMEOUT" warning message. To exit the overtime condition, set the OFF/Auto/ON switch to "OFF" position, and then to "Auto" again. [. . . ] Switch for selecting dosing mode: · OFF = dosing disabled · Auto = automatic dosage, depending on setpoint value and dosing selection · ON = dosing always active 3. "MEAS" key to set the instrument to measurement mode 4. "SET" key to display and set the setpoint value 5. [. . . ]