Find Hidden Loop Problems with Ground Leak Detection
If you find a loop where the transmitter is calibrated correctly but all the readings elsewhere in the loop have a fixed offset this is due to a Zero Shift. This zero shift is typically caused by some current in the loop bypassing the transmitter. This might be caused by ground faults, moisture or corrosion.
Turn on Ground Leak Detection and use the PIE 434 to power up the loop. Any current that isn’t controlled by the transmitter or other current control element will be indicated as leakage on the calibrator’s display.
Typical problem found with Loop Diagnostics
Here is a loop where a technician has just recalibrated the transmitter but the control room still sees a problem. The problem started just after a rainstorm.
Using a PIE 434 to power the loop the technician detects a leakage of 0.51 mA – the same offset seen in the control room. He walks the loop and opens a junction box releasing a stream of water. The loop is again in control. Clink on the link below to see a video demonstration of Loop Diagnostics in action.
Video Demonstration of Loop Diagnostics
Advantages of the PIE 434 Automated Diagnostic Calibrator over the Altek 434 Milliamp Calibrator
- Larger Display with Backlight
Easy viewing in dark locations
- Easy selection of 250 Ω Hart Compatible Resistor
No disassembly to move internal jumper
- Find Loop Current Leakages
Measure ground current leakage from faulty wiring, flooded conduit and corrosion bridges. Leakage appears as a Zero Shift and helps you decide if the transmitter needs calibration or if there is some problem in the loop wiring.
- More Resistant to Accidental Damage
Rubber Boot and Stronger Switches
- Less Expensive Battery Changes
Four versus six “AA” batteries
- Includes Certificate of Calibration
All PIE Calibrators come with a free signed and dated certificate. Altek’s come only with an unsigned Statement of Calibration Practices with a certificate of calibration available for an extra charge.