Sigra supplies a range of pressure transducers principally, but not exclusively, for use in borehole applications. These may measure absolute pressure or gauge pressure with respect to a vent line.
Because analogue outputs of voltage or current loop form are easily corrupted by line resistance or leakage between conductors, all of Sigra’s borehole sensors have a digital output of some form. This may take the form of:
- Vibrating wire transducer frequency output
All of these outputs are compatible with the Sigra Field Data Logger (qv) which has 24 bit sensitivity on frequency and vibrating wire applications, and 16 bit sensitivity for analogue inputs. We can obtain sensitivities of one part in a million with some transducers.
The transducer types we supply for these applications are both vibrating wire and bridge type devices. We calibrate all the transducers we supply to traceable standards of pressure, and at a range of temperatures. We can therefore be certain of the accuracy and sensitivity of the devices that we supply.
We normally supply pressure transducers fitted with a suitable cable for installation in a borehole. The cable types that may be used are:
- Gel filled polyethylene
- Gel filled polyethylene with a support strand
- Armoured cable
- Tubing Encapsulated Cable (TEC)
- PTFE insulated for high temperature applications
We can also supply transducers fitted to our range of packers for permanent monitoring single or multiple locations within a borehole (qv).
Sigra uses its own transducers in cemented permanent reservoir monitoring applications (qv).
Sigra has very sensitive low range vented pressure sensors for use in stream or surface reservoir monitoring (qv). These come in versions for 0.7, 3.5, 10 and 20 m water head.