HDM-135A (2-wire system) HDM-136A (4-wire system)0 pages

HDM-135A (2-wire system)
HDM-136A (4-wire system)

pH Transmitter

The pH transmitter is a user-friendly device that
features a compact and robust aluminum case, making it
ideal for on-site installation.
This device comes in two different models: the 2-wire
system (24VDC power supply) and the 4-wire system
(adjustable-voltage AC power supply).
Features
Simplified calibration with standard solutions
The data for up to five different pH standard solutions can
be stored in the internal memory for single-action
calibration. Stability judgement function provides accurate
calibration with standard solutions, free from operator error.
Automatic determination of electrode quality
The transmitter judges the electrode quality from its
characteristics during calibration with standard solutions.
Degradation of electromotive force at pH7, degradation o
felectromotive force per pH and other information is
displayed in the form of error messages. Characteristic
data of each electrode can be called out to determine the
extent of degradation as required.
Temperature display
The analyzer/transmitter measures and displays the
temperature of samples and standard solutions using a pH
electrode equipped with an internal temperature sensor
(5600, GSS-304B, or other model).
Output hold while performing maintenance work
When the transmitter enters maintenance (ST-BY) mode,
the previous output value is held. This helps to prevent
disruptions to the control system.
Measured value shift
Measured pH values can be shifted for operational control.
(Shift width: ±1.0pH)

Manual temperature compensation
Manual temperature compensation function (0-100ºC) can
be provided for use with electrodes which do not have
compensation functions.
pH temperature compensation
The transmitter compensates the pH temperature
characteristics of samples (such as pure water and boiler
water).
Setting range of temperature compensation coefficient :
±0.1pH/ºC
Standard conversion temperature: 25ºC
Self-diagnostics
The transmitter detects damage on the glass membrane,
problem with temperature compensation resistance,
hardware failures and abnormal data. If a fault is detected,
the transmission output is switched to the upper or lower
limit to notify the fault (burn-out function).
Automatic reversion to measurement mode
The analyzer/transmitter automatically switches back to
measurement mode if it is left in maintenance mode for
more than two hours.
External input for “hold” feature (option)
The transmitter can receive a “hold” command signal from
the cleaning devices to hold output during the cleaning.

System configuration
Transmitter
HDM-135A

2-wire system
Detector

Site

Instrument room

Power/Transmission output (24VDC 4~20mA)

Electrode lead

Receiver

Indicator
Recorder
Controller
DCS, etc.

Receiver

Indicator
Recorder
Controller
DCS, etc.

Distributor

(5m or 10m)
DC power

HC type
Transmitter
HDM-136A

4-wire system
Detector

Electrode lead

Site

Instrument room

Transmission output (4~20mADC)

(5m or 10m)

HC type

Instrumentation power
100~120VAC
or
200~240VAC