
Industrial pH Two Wire 4 to 20 mA Transmitters
PHTX-212/PHTX-014 
U Isolated or Non-Isolated Models Available 
U 4 to 20 mA Output 
U Manual or Automatic Temperature Compensation
The model PHTX-014 pH two wire transmitter is designed  
to provide a standard 4 to 20 mA current output which is 
proportional to the pH being measured. Its small size and 
encapsulated construction allow for easy installation and  
will accommodate any pH electrode with a BNC connector. 
Temperature compensation is either manual or automatic  
with use of any 1000Ω Platinum RTD.
The PHTX-212 is the same as the PHTX-014 but with a range  
of 2 to 12 pH. This is a popular choice for use with recorders  
or any application where it is convenient to divide the output into 
ten divisions.
The PHTX-ORP is for an ORP electrode input with a range of  
0 to 2000 mV.
The PHTX-11 features include a NEMA-4X housing,  
an integral LCD display for continuous pH reading or for  
a direct corresponding readout in milliamps, using a convenient  
push-button switch. The 4 to 20 mA output signal may be  
scaled in the field to meet specific pH ranges in any 1 to  
14 pH unit increment. Temperature compensation is manual  
using a fixed resistor or automatic using any of OMEGA’s  
700 Series thermistors.
PHTX-014,  
non-isolated 2-wire  
transmitter, shown  
smaller than actual size. 
Specifications
Range: 
 PHTX-014: 0 to 14 pH 
 PHTX-212: 2 to 12 pH 
 PHTX-ORP: 0 to 2000 mV 
 PHTX-11: Any 1 to 14 pH units, user selectable output 
Accuracy: 
 PHTX-014, PHTX-212, PHTX-11: ±0.02 pH 
 PHTX-ORP: ±1.0 mV 
Operating Temperature: 
 PHTX-014, PHTX-212, PHTX-ORP: -25 to 70°C (-13 to 158°F) 
 PHTX-11: -10 to 60°C (14 to 140°F)
Input Impedance: > 10 
Temperature Compensation: 
 Manual: fixed resistors;  
 Automatic: PHTX-014, PHTX-212: 1000 Ω platinum RTD 
 PHTX-11: OMEGA’s OL-700 series thermistor
Connector: BNC 
Power: 12 to 80 Vdc (24 Vdc recommended) 
Output: 
 PHTX-014, PHTX-212, PHTX-ORP: Non-isolated 4 to 20 mA 
 PHTX-11: Isolated 4 to 20 mA 
Input to Output Isolation:  
 PHTX-11: 600 V max 
Dimensions: 
 PHTX-014: 50.8 H x 38.1 W x 24.1 mm D (2 x 1.5 x 0.95") 
 PHTX-212, PHTX-ORP: 57.4 H x 38.1 W x 38.1 mm D  
 (2.25 x 1.5 x 1.5")  
 PHTX-11: 125 H x 74.2 W x 99.6 mm D (4.92 x 2.92 x 3.92") 
Display:  
 PHTX-11: 3 
Display Resolution:  
 PHTX-11: 0.01 pH
1
⁄2 digit LCD
13
 Ω
PHTX-11, isolated  
4 to 20 mA transmitter, 
shown smaller than actual size. 
 To Order Visit omega.com/phtx014 for Pricing and Details
 Model No.  Description
 PHTX-212  Non-isolated 2 wire pH transmitter, 2 to 12 pH 
 PHTX-014  Non-Isolated 2-wire pH transmitter, 0 to 14 pH 
 PHTX-ORP  Non-Isolated 2-wire ORP transmitter 
 PHTX-11   Isolated 4 to 20 mA pH transmitter with integral 
 PSS-D12B  12 or 24 Vdc power supply
Comes complete with operator’s manual.
Ordering Examples: PHTX-11, isolated 4 to 20 mA transmitter,  
PSS-D12B, power supply.
PHTX-014, non-isolated 2-wire pH transmitter, PSS-D12B power supply.
display, NEMA-4X enclosure
D-29
Our Industrial pH Instrumentation and Electrodes product 
line continues to expand, visit omega.com for new details!
For Sales 
& Service
U.S.A. and Canada