| There is no response from the transducer! |
1.) Verify that the transducer is receiving the correct excitation as shown on the Calibration Certificate. |
|
2.) Verify that the transducer is wired correctly and that the leads are not damaged. Use a DMM to ohm out the leads to ensure continuity.
3.) Make sure that there is nothing obstructing the pressure port that may impede the flow of pressure.
4.) If possible, replace with another GP:50 Pressure Transducer to determine if the same failure is occurring. If yes, check the system. If no, then you may need to return the unit for repair or replacement (Return Warranty)
5.) As an added option, and prior to returning the unit, you may contact the factory for further technical support.
|
|
Technical Notes
A) If the transducer is pulling current, is reading 0 output, or the reading is static, the unit may have seen a power surge. Power surges are a common occurrence after a storm.
Please follow this link for more information regarding surges.
B) Causes of overpressure include system failure, frozen lines, and spikes from high-cyclic applications. When a unit is overpressurized it will generally exhibit one or more of the following conditions: a large positive zero shift, diaphragm bowing or rupture, decreased FSO and a decrease in linearity.
|
| It's noisy |
Check to see if the pressure transducer is grounded to the equipment and the power supply is grounded to the shield. In the event that this situation exists a ground loop may be induced. Either isolate the pressure transducer from the grounded equipment or disconnect the shield off of the power supply ground terminal. |
|
2.) For a high resolution applications contact GP:50 for application assistance.
3.) Measure the output of the power supply with an oscilloscope (an acceptable amount of AC ripple for most applications is 5 mV peak to peak). If the power supply appears to be noisy, add a filter capacitor from positive supply to ground. A good start would be a 10 microfarad, 35 Vdc Tantalum Capacitor.
4.) Call GP:50 for further technical support (the Return Warranty policy may apply).
|
|
Technical Notes
A) A motor or pump that is in close proximity to the transducer by may be generating RFI / EMI signals. GP:50 has options available to suppress errors due to this type of interference. Contact us for more information.
B) A switching type of power supply may generate unwanted noise at the output of the pressure transducer. Call GP:50 for application advice on eliminating this unwanted signal.
|
| The transducer is out of calibration |
1.) Check that the transducer is the correct range. |
|
2.) Verify that the transducer is wired correctly and that the correct excitation is being used.
3.) Verify that the transducer is being operated within its temperature compensation range.
4.) Check for pre-load on the transducer
5.) Check for system leaks.
6.) If the transducer has zero and span adjustments use the following procedure.
7.) Call GP:50 for further technical support (the Return Warranty policy may apply).
|
|
Technical Notes
A) For gauge pressure technology, the lifetime of a transducer is approximately 10 million cycles. This number is not exact and can vary with temperature, age, cyclic rate, and application.
B) High-cyclic applications can sometimes cause a pressure shock. This shock, although not an overpressure, can cause permanent damage to the sensing diaphragm. GP:50 has transducers that will meet the demand of these applications. Contact us for more details.
C) Model 10 and Model 16 Pressure transducers were specifically designed for low range applications, and as such are inherently sensitive to the slightest pressure. To achieve this level of sensitivity we utilize an oil-filled variable capacitance sensing technology. The oil serves as our dielectric, which provides the best stability performance presently available. This oil has a mass which will affect the unit's performance as presently available. Specification Engineers should be aware of the following when applying these units:
Position Sensitivity
All units are calibrated with the pressure port in the horizontal position. As the unit is rotated out of the horizontal the zero of the unit will change. The change will vary depending of the degree of rotation with the maximum change being approximately equal to 1". This position sensitivity does not affect accuracy or temperature performance and the resulting shift should be within the ability of the unit's zero adjustment range to offset (or re-zero).
Vibration / Shock Sensitivity
As these units are fluid-filled and the fluid is contained between passive foil diaphragms, the fluid will 'oscillate' when the unit is vibrated (or shocked), again, causing a respective (temporary) change in the zero of the unit. These units have been tested to 20 G's in various axis with no damage or permanent shift to the unit.
Both the Model 10 and the Model 16 are built with an all-welded, NEMA-4 construction with zero and span adjustments as standard to provide a ruggedly constructed unit with high performance at a low cost.
|
