On-Line pH Transmitter

On-Line pH Transmitter

The CD pH / Redox Transmitter is state-of-the-art solid state high impedance amplifier which interfaces the low current pH or Redox signals to digital process indicators or other slave instruments. Switchable spans of 5 & 10 pH can be set up within the 0 to 14 pH scale. With Automatic temperature compensation the transmitter ensures high accuracy under all temperature conditions. The features of this instrument make it suitable for water treatment, effluent treatment and process control applications.

FEATURES

Accurately measures pH and ORP parameters
Designed to withstand the arduous conditions found in industrial environments, whilst retaining accuracy and sensitivity of laboratory instruments.
Temperature compensation fixed or automatic
Can be surface mounted close to the sample point or inside a control panel
Virtually immune to AC line noise, switching spikes and fluctuations shocks and vibration stresses, temperature and humidity variations
Easy-to-connect high impedance push fix connectors for solderless wiring

Both reference and pH/Redox inputs are high Ohmic giving a high degree of protection against electrical interference
Output currents for electronic or pneumatic slave instruments (Operation of Pneumatic instruments needs an additional E/P convertor)
Comprehensive test and reliability procedures ensure long term Reliability and sustained high performance
Robust, fully enclosed shielded metal case keeps out dust, dirt and chemical contaminations.

The Alchemie pH Electrode is a robust and accurate electrode with very low alkali error. These high repeatable electrodes provide accurate readings with fast response time. As applications demand reliable sensors, the performance of a typical pH sensor depends upon the reference cell to produce a stable and constant voltage independent of the process conditions. Alchemie pH Electrodes stand up to these stringent specifications.

The CD pH Electrode Housing has the widest available range of electrode and automatic temperature compensator options, making it ideal for high-purity water measurement with solution ground. The ultrasonic cleaner option is a plus for processes with deposit problems. The housings are available in SS316, Polypropylene and Teflon with numerous mounting configuration options, including online and immersion mountings. A guard ring tube protects the high impedance glass electrode input from electrical leakages occuring due to submersed electrical equipment.

Transmitter Specifications :

Analog Input
Configuration :	Unipolar differential
Bias current :	<10 ^{- 12} amps for both pH and reference electrode Inputs
Input Impedance :	>10 ¹² Ohms for both pH and reference electrode Inputs
Analog Output
Full Scale Measuring Ranges :	(pH 0 - pH 10) / (pH 0 - pH 5) (pH 1 - pH 11) / (pH 1 - pH 6) (pH 2 - pH 12) / (pH 2 - pH 7) (pH 4 - pH 14) / (pH 4 - pH 9) (pH 7 - pH 14) / (pH 7 - pH 12) Corresponding ranges in millivolts. 20 ranges possible between -1000 to +1000 mV.
Output Current :	0 - 20 mA DC Dead Zero ; convertable to 0 - 5 V DC 4 - 20 mA DC Live Zero ; convertable to 1 - 5 V DC
Max. Load resistance :	500 Ohms (10 V) at 300 meters.
Signal Conditioning
Temperature Compensation :	Automatic between -10°C to +150°C using PT100 Platinum Thermocompensator "APX 140"
Asymmetry correction :	± 60mV / ± 120 mV ± 1 pH / ± 2 pH
Slope Correction :	90 to 105% at 25°C of Nernst value
Accuracy & Stability
Linearity :	Linearity error less than ± 1% FSD
Reproducibility :	Better than ± 0.1% FSD
Stability :	Drift after 1 hour of operation better than 0.01% FSD in 24 hours With fluctuating ambient temperature better than ± 0.25% FSD/10°C
Common mode range :	Max. ± 10V DC ± 10V AC (Peak value)
Influence of load variation :	< 0.1% FSD for 500 Ohms change.
Power :	230 Volts AC single phase / 110 volts AC single phase 24V DC +20% -10% 3 Watts maximum
Environmental, Physical & Reliability
Temperature Range :	Operating 0°C to 60°C Storage -25°C to 85°C
Relative Humidity :	0 to 95% non-condensing
Warm up Time :	5 minutes
Over voltage :	Power : 260 volts max. 200 volts min. Input : 2 volts max.
Case :	Die Cast aluminium, weather and splash proof
Mounting :	Surface mounting or Panel mounting on three bolts.
Digital Display
Local Digital Readout :	3 ½ digit (LED or LCD) 0.5" height 7 segment display