pHionics STs Conductivity Sensor/Transmitter

pHionics has combined a conductivity and temperature sensor with a 4-20 mA transmitter into a single, compact device that provides exceptional durability and accuracy. The 4-cell electrode with removable guard allows for easy cleaning and prevents common problems such as polarization and debris build-up that would otherwise interfere with measurements of conductivity, salinity, or total dissolved solids. Our electrode is also made with chemical-resistant Delrin which allows us to extend our 2-year warranty to the electrode as well (The electrode and sensor/transmitter can last up to 20 years with proper care).

Combined with the small diameter (0.75) to reduce installation costs, the features of the pHionics STs Series™ Conductivity Sensor/Transmitter guarantee accurate conductivity measurement and excellent long-term value.

Features and Benefits

- Noise Reduction: From crystal-clear streams only touched by radio frequencies to wastewater treatment plants surrounded by heavy machinery, background noise and interference is everywhere. Our signal conditioning removes background (common-mode) noise from the measurement to ensure high accuracy. The signal is also sent through a preamplifier to strengthen it before traveling through a twisted-pair, shielded cable that protects the amplified 4-20 mA signal until it reaches the datalogger or controller.
- Ease-Of-Use: Typical 2-wire transmitters are relatively easy to set up but improper wiring can result in damage to the transmitter or expensive controller. The STs Series prevents damage with a reversible input protection so the two wires per parameter can be switched without performance issues. Additionally, all parts are quick and easy to replace without any special tools. This cuts down on maintenance time and costs, especially in circumstances where cable damage requires complete replacement of normal sensors and transmitters.
- Isolation: Isolation removes ground loop interference to save troubleshooting time and money by preventing damage to connected electronics in the case of power surges up to 600V. This allows the STs Series to be used in process control applications without worrying about different grounding potentials of the solution or mounting surface. It has the added benefit of protecting connected devices if exposed to large amounts of current caused by damaged machinery or improper wiring.
- Low Power Usage: Sensors and transmitters made by other competitors commonly use more current than the 4-20 mA signal to power their devices, ranging from 3-15 mA additional. pHionics only ever uses the amount of current required for the signal, allowing STs Series devices to function between 60% to 375% longer on the same battery. The STs Series also only requires 8 VDC and has a three second turn-on time, further reducing power usage.

Available ranges:

- 0 to 100 uS, 2x 4-20 mA
- 0 to 1000 uS, 2x 4-20 mA
- 0 to 10,000 uS, 2x 4-20 mA
- 0 to 100,000 uS, 2x 4-20 mA
- 0 to 5,000 uS, 2x 4-20 mA

Specifications

2-wire, 4-20 mA Conductivity Sensor/Transmitter:

- Output: 4-20 mA
- Electrode Type: 4-cell
- Automatic Temperature Compensation: 2% per C
- Isolation: 600 VDC
- Power Supply Voltage: 8 to 40 VDC
- Loop Impedance (Max): 200 Ohms at 12 VDC/800 Ohms at 24 VDC/1600 Ohms at 40 VDC
- Response time: 95% less than 5 seconds
- Pressure Range: 0-100 psi
- Wetted Materials: 316 SS, Delrin, Viton, glass
- Length: 13.5 in (34.3 cm)
- Width: 0.750 in (1.9 cm) maximum
- Weight (No cable): 0.50 lbs (0.227 kg)
- Linearity: +/- 0.20% of full scale
- Accuracy: +/- 0.20% of full scale
- Sensitivity: +/- 0.05% of full scale
- Stability: +/- 0.10% of full scale
- Repeatability: +/- 0.10% of full scale

2-wire, 4-20 mA Temperature Sensor/Transmitter:

- Output: 4-20 mA
- Temperature Range: 0 to 50 C
- Power Supply Voltage: 7-40 VDC
- Loop Impedance (Max): 250 Ohms at 12 VDC/850 Ohms at 24 VDC/1650 Ohms at 40 VDC
- Isolation: 600 VDC

Cable:

- Cable Material: Polyurethane
- Type: 4 conductor, Kevlar reinforced, water blocked, shielded, twisted-pair wiring
- Maximum Distance: 3 miles
- Replaceable?: Yes