Hofmann DPH-64 User manual

DIGITAL
pH/mV
CONTROLLER
DPH-64
USERS GUIDE
DPH-64 Instruction manual PAGE 1

TABLE OF CONTENTS
SPECIFICATIONS ................ 3
INTRODUCTION ................. 5
INSTALLATION ................. 8
Instrument ................... 8
Wiring of the DPH-64 ............. 9
Electrodes ................... 9
Starting up the Instrument. .......... 9
CONFIGURATION ................ 10
Default values for the DPH-64 instrument . . 10
Configurations for the DPH-64. ........ 11
Calibrating pH or mV ............. 11
Setting Time and Day ............. 12
Calibrating 4mA and 20mA with a multimeter. 12
Changing mode of operation. ......... 14
Extended Features .............. 16
Timed relays .................. 17
S1 relay used as a TIMER .......... 18
S2 as ALARM RELAY. ............ 18
S3 / S4 with DELAY .............. 18
S3 / S4 Proportional .............. 19
S3 / S4 Temperature ............. 19
4-20mA SETPOINT .............. 20
P1 / P2 Pulse output. ............. 21
Reset to Defaults ............... 22
WIRING GUIDE ................. 23
PAGE 2 DPH-64 Instruction manual

SPECIFICATIONS
Range: 0-14pH 0.01 pH resolution
+1000mV 1mV resolution
Display: Dot matrix 4 line by 20 character backlid LCD display
Electrode: BNC external of housing.
Temperature: (pH only) manual or automatic temp. Compensation
0-100 oC.
Signal output: 4-20mA, electrically isolated from instrument.
4-20mA range software selected between 0 to 14pH
or 0 to +1000mV. Maximum termination impedance to
drive 20mA is 1000 Ohms.
Can also be setup to follow setpoint for signal driven
metering pumps.
Relay outputs: 2 relays (S1 & S2) switched active with neutral and
earth terminals. Contacts rated 240V 5AMPS
(non-inductive)
2 relays (S3 & S4) with potential free changeover
contacts. Timers can be activated to enable / disable
relay outputs for programmed times.
Set points: All relays can be configured for up/down dosing.
Enable a Time delay of 1 to 5 minutes between
S3 & S4 if acid / alkaline dosing is required.
DPH-64 Instruction manual PAGE 3

Clock: Real time clock with AM/PM or 24H mode. Battery
backed up.
Additional
relay functions: S1 can be set up as a timer with real time
ON/OFF timing.
S3 and S4 can operate in proportional mode.
S3 and S4 can also be lprogrammed to track
temperature for temperature control or alarm.
S2 configurable as a high/low alarm.
Pulse output: P1 and P2 are (contact closure) non-polarised pulsed
outputs. Minimum pulse duration 250mS. 500 volt
isolation to instrument output. Maximum voltage
across terminals 100 volts.
Pulse rate: Select maximum pulse rate per minute from 50 to 100
pulses. Slope of pulse frequency 0.5pH to 2pH
above/below SET POINT.
Power supply: 240V/50H 8VA max.
Construction: Fully sealed construction with hinged clear acrylic
front cover. IP55 specifications.
Dimensions: (W)215mm x (H)185mm x (D)115mm.
PAGE 4 DPH-64 Instruction manual

INTRODUCTION
The 4 line by 20-character LCD display allows text messages or
prompts in “real” language without confusing abbreviations.
Encoder knobs are rotated to scroll through different menus, values or
changing set points. Once a mode of operation, calibration value or
setpoint is dialled simply push the encoder knob to select. All custom
configurations are stored in non-volatile memory.
A real time clock is always present and each relay output can be linked
with a timer to operate only at programmed times.
The signal generated from a pH electrode is extremely weak with a very
high impedance and therefore very sensitive to electrical interference.
This necessitates the use of shielded cable for the connection of the
electrode. A coaxial cable with an additional outer layer of carbon must
be used to ensure a steady pH signal. The DPH-64 converts the electrode
signal with a precision input amplifier and then further processes the
electrical signal for display, alarm, signal and set point controls.
.1/  DPH-64 pH / ORP controller
DPH-64 Instruction manual PAGE 5