text.skipToContent text.skipToNavigation

Differential pH or ORP Probes


Item# PHETX-610

Volume discounts available
Volume Discount Schedule
Quantity Price each
1-4 $712.83
5-9 $677.19
10-24 $662.93
25-49 $634.42
50-99 $620.16
100+ $605.91

In stock

Lead Time ( If not in Stock): 2 weeks

Differential pH or ORP Probes PHETX-610 PHETX-610
  • Integral 2-Wire 4 to 20 mA Transmitter
  • Accurate Differential Measurement
  • Eliminates Ground Loop Interference
  • Built-In Pre-Amp Supports Up to 914 m (3000') Sensor-to-Analyzer Distance
  • 4.6 m (15') Standard Cable Length
  • Automatic Temperature Compensation on pH Versions

Edit Options

View all models

Not all combinations are valid. Options compatible with previous selections will be in bold.

*Highlighted options are not compatible. Please select a different combination.

Measurement Type
Wetted Materials
Max Operating Pressure
Max Temperature
Process Connection Type
Process Connection Size

Product Specs

OMEGA™ pH and ORP differential probes stay in service and provide accurate measurements under conditions that often render conventional pH probes inoperable. These probes, come with an integral encapsulated 4 to 20 mA 2-wire transmitter to feed directly to a PLC or a DCS.
The PHETX-600 and ORETX-600 probes employ a differential measurement technique. Unlike conventional combination probes, the differential probe has two high impedance measurement circuits containing a common metallic return electrode. One circuit includes the process measurement electrode which generates a potential E1 proportional to the process pH. The second circuit includes an internal measurement electrode immersed in a stable buffer solution which generates a standard reference potential, E2. Both circuit share a common potential E3 developed at the return electrode. The two circuits are fed into amplifiers which provide an output representing the differential between them: (E1 - E 3)– (E2 - E3). The common potential E3 is cancelled out electronically, greatly reducing inaccuracies caused by ground loops which may exist between process and instrument grounds. Ground loop current will flow through the low impedance path of the return electrode, affecting the potential E3, but not the differential measurement.
The differential probe maintains its accuracy and stability in aggressive process applications long after a combination-style probes performance begins to deteriorate. Maintenance costs are reduced and the life of the probe is increased. The internal reference electrode is electrically connected to the process solution by means of a field-replaceable double junction salt bridge which greatly reduces the possibility of contamination of the buffer solution in the reference circuit. Although seldom required, the reference solution may be easily replaced by removing the screw-out salt bridge. A salt bridge and buffers are available for this purpose.
Another advantage of the PHETX/ ORETX-600 series are the semi-flush face which is easily cleaned and avoids solution materials gathering on protrusions found in other probes. The domed glass electrode, the protective metal electrode and the temperature sensor protrude only about 18" while the salt bridge is flush. A flat-face version of the pH probe is also available. The PHETX/ORETX-600 series is available in: 1½ NPT threaded body style (-600), “easy-in, easy-out” variable insertion depth version with 1¼ NPT compression fitting (-610), or the hot tap version (-620).

Measuring Range:
pH: 0 to 14 pH (consult factory for applications below 2 or above 12)
ORP: -500 to 500 mV or 0 mV to 1000 mV, field selectable
Flow Rate: 10 ft/sec max (3 meters/sec) flow should be as low as possible in low conductivity water and in solutions with high suspended solids
Wetted Materials: CPVC, kynar, glass, titanium palladium alloy and EPDM (platinum for ORP probe); opt FKM and ceramic
Transmission Distance: Dependant upon transmission distance and supply voltage 1
pH: 0.001 pH
ORP: 0.1 mV
pH: 0.03 pH per day, non-cumulative
ORP: 2 mV per day, non-cumulative
Temperature Compensation (Automatic): -5 to 95°C (23 to 203°F)
Pressure Limit: 100 psig at 65°C (149°F) max
Temperature Limits (CPVC): -5 to 95°C (23 to 203°F) the temperature limit of probes in flow through applications is limited by pressure and by the pipe fitting material.
Probe Cable: 4.6 m (15') long

  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • LOCAL, getReviews, 0ms
  • bvseo-msg: The resource to the URL or file is currently unavailable.;

Do you sell separate compression fitting for model PHETX-610 ph sensor

Asked by: naleway
Thank you for your inquiry on this product. Unfortunately, no.
Answered by: JC ENGR
Date published: 2020-09-18

I would like to connect the PHETX-610 to a NI DAQ device that supports the 4-20 mA output of this pH sensor. Does Omega provide LabView code that is need for conversion of mA output back to pH? And instructions for re-calibrating the curve as needed?

Asked by: Vikram
Thank you for your inquiry. Unfortunately, no and it is a direct 4 to 20 mA output where 4 mA is equal to 1 pH and 20 mA is equal to 14 pH, proportionally.
Answered by: Applications Engineer JC
Date published: 2020-11-16
  • y_2021, m_9, d_23, h_20CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.19
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_2
  • loc_en_US, sid_PHETX-610, prod, sort_[SortEntry(order=NUM_ANSWERS, direction=DESCENDING)]
  • clientName_omega
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • LOCAL, getContent, 3ms
Differential pH or ORP Probes
0 In Stock
Replacement salt bridge kit for 600 Series
0 In Stock
Electrode protector for 600 Series
0 In Stock
10.01 pH buffer solution 475 ml bottle
50 In Stock
pH 10 buffer solution, 4L (1 gal)
20 In Stock
pH 4 buffer solutions, 500 ml (1 pt)
44 In Stock
pH 4 buffer solution, 4L (1 gal)
19 In Stock
7.00 pH buffer solution, 500 ml (1 pint) bottle
46 In Stock
PH 7 buffer solution 4L (1 gal)
4 In Stock
De-ionized water 500 ml (1 pt)
14 In Stock
De-ionized water, 4L (1 gal)
9 In Stock
5 each single use foil packets of pH-4, pH-7, pH-10, and de-ionized water
10 In Stock
20 foil packets of de-ionized water
8 In Stock
pH Accessories
PVC hot tap ball valve assembly
0 In Stock
This item is no longer available to purchase. For questions contact sales

Save Configuration