DeviGyro FAQ Page

DeviGyro Frequently Asked Questions

DeviGyro Specifications

Is the DeviGyro North-seeking?

The DeviGyro is not a North-seeking Gyro in the true sense of the word. It is a high precision continuous rate gyro using North-seeking principles and proprietary algorithms to determine the drill hole path from a known direction.


Most continuous North-seeking gyros operate in the same way. They determine a start direction and then measure the “rate“ of change from the initial reference.


Downhole Surveys recommends combining the DeviGyro with an Azimuth Aligner in order to get a powerful North-seeking system that is superior to existing North-seeking borehole tools. Enquire about our reduced package pricing today.

What is the size of the DeviGyro sensor?

25mm x 110mm. It can fit in your pocket it’s that small!

Does the DeviGyro have any limitations with respect to borehole angles or latitude?

The DeviGyro can survey all angles.


Downhole Surveys are currently only releasing to the Surface RC and Diamond markets, with releases catering to underground up-hole applications coming soon.

DeviGyro Operation

What is the DeviGyro's maximum operating speed?

The DeviGyro’s maximum operating speed is 180m/min, however Downhole Surveys recommends the DeviGyro be operated at a safe running speed of 60 – 80m/min.

Do I need to stop the continuous survey at any time?

Yes a zero velocity update is required every 10 minutes for a period of 15 seconds. The DeviGyro App prompts the user for the stops.

Does the DeviGyro require a warm-up period?

There is no gyro warm up time required. However, best practice is to allow the DeviGyro time to temperature stabilise to the environment it is working in.

Can I tie on a Survey?

Yes a tie on survey can be conducted, however best practice is to conduct a new survey each time from the collar and apply weighted averaging to increase the survey precision.

DeviGyro Equipment

How long is the DeviGyro when assembled?

Approximately 2.2m

What running gear is supplied with the DeviGyro?

The DeviGyro sensor is housed in a 40mm OD small brass barrel. Aluminium spacer rods are added to lengthen the assembly and a set of centralisers provide rotation at a controlled rate. A shock sub is added to the bottom section for protection and a range of top sub adaptors are available. Most common is a spearhead or wireline swivel.


All components are supplied in a single rifle case weighing approximately 25 kg.

What is a DeviCounter and do I need to use one?

A critical component supplied with the continuous DeviGyro is the optical depth encoder, the DeviCounter. The Devicounter is attached to the drill rig wireline, recording time and depth, whilst the DeviGyro records time and navigation data. After surveying is completed the two sets of data are merged.


Unlike some counter systems the DeviCounter stores the depth data internally, correcting errors prior to merging.


The DeviGyro can also be run in manual mode where a depth interval is manually entered, for example when using a fibre glass rodder or polypipe.

Survey Results and Accuracy

How accurate is the DeviGyro?

0.2% of hole depth

Ready to achieve absolute precision on your next drill campaign?