1. ER & LPR Monitoring Systems

2. Popular Corrosion Monitoring Techniques
Weight Loss Coupons
Linear Polarisation Resistance Probes (LPR)
Electrical Resistance Probes (ER)
CEION Probes
Hydrogen Probes
Biofilm probes

3. Weight Loss Coupons

4. Weight Loss Coupons 3 inch strip coupons before cleaning
3 inch strip coupons after cleaning

5. Top of line
Middle of Line
Bottom of Line
3” Strip (pair)
Multi –disc
6” Strip (pair)
Flush Disc
Ladder Strip (pairs)

6. ER: The Ratiometric Principle
SAMPLE
REFERENCE
The ratio of sample & reference elements resistance is a measure of the corrosion affecting the exposed sample element by a reduction in its surface area and therefore increase in its resistance. The ratio Rs/Rr is converted to metal loss in the measuring instrument. The slope of the metal loss curve is the corrosion rate

7. ER Probes Can be used in all systems (Gas, Water, Oil)
Can measure erosion
Low sensitivity
Thinner elements improve sensitivity
At the cost of probe life.
Typical Flush Probe (High Pressure System) showing F20 (0.5mm thick element) Lifetime ½ element thickness

8. ELECTRICAL RESISTANCE (ER)

9. ELECTRICAL RESISTANCE (ER)
Wire Loop Probe 1.0mm (40 thou’) element Lifetime ¼ of probe thickness

10. ER Wire loop probe with velocity shield in 2” HP access fitting

11. Tubular ER Probe (left) in retractable assembly. Max pressure 1000 psi

12. DCU3 Data Logger ER or LPR Configurations
4000 readings storage
ATEX/CSA approval
Also transmitter capability
Probe mounted for HP applications, panel mounted for LP (retractable) assemblies

13. Linear Polarisation Resistance (LPR)
Theory of Operation
The theoretical basis of the LPR technique was founded in a publication dating back to 1957.
In the LPR technique, a potential (typically of the order of mV) is applied to a freely corroding sensor element and the resulting ("linear") current response is measured.
The current measured in a conductive solution ie., a continuous phase of water is proportional to the ‘corrosion’ current and is converted to corrosion rate by multiplying the measured value by a conversion factor depending on electrode size and electrode material

14. Probes Linear Polarisation Resistance (LPR) Instant corrosion rates
Used in conductive systems
Can’t be used where oil is present
Can’t be used in gas systems
Typical flush mounted 3-electrode probe

15. ACCESS SYSTEMS RETRACTABLE
Flanged LPR assembly with protruding electrodes

16. LINEAR POLARISATION RESISTANCE (LPR)

17. Multi-Function instrument HHU-M for upload from data loggers (ER & LPR configurations) and reading ER & LPR probes directly

18. THANKS