Frequently asked questions

This highly depends on the carefulness of the operator when inspecting where to conduct drillings. You want to avoid any nails or metal plates in any wood products as much as possible to preserve the bit. You will also need to be careful and aware of what type of substance the needle will exit through whether it’s sand, soil, granite or etc.

With the IML-RESI PD-series, you can perform approx. 200 measurements per battery charge (battery: 18 V, 5.0 Ah). With the IML-RESI F series, you can perform approx. 50 measurements per battery charge (battery: 18 V, 4.0 Ah).

The drills are approximately 5-7 kg depending on the size of the drill. We always recommend anyone purchasing a drill to opt-in for the handle and stability strap. When you are conducting inspections on an all-day basis it’s safer, secure and ergonomic to have the drill strapped to you to reduce any damages that may incur.

One of the best features of our drills, especially for arborists working in the field of inspecting live trees, is the fill-in methods of the bits. Our bits are 3mm and while they are already small in size, when the needle retracts it pulls the wood back in to fill the hole. Immediately after you would not be able to stick the bit fully back in the hole that was drilled. As time goes on the tree seals the hole.

Yes, the drill can inspect when it is in freezing weather. However, decay can also freeze and show a higher resistance than above freezing. However, you can still detect decay with the change in the resistance if the decay is frozen.

The standard inspection drills are water resistant, not waterproof. You will want to treat the drill as you would your smart phone of other electronic devices that are water resistant.

Since the drills are measuring devices we recommend an annual calibration to confirm that you are receiving accurate inspection readings. The calibration machine checks to see if the motor is still rotating at the correct revolutions per minute and the force to move the needle forward is within specifications. This ensures you’re gathering accurate and proper results.

Our service team can get a drill in and out of our office within two-days-time as long as there are no pending questions for the customer. If you need your drill returned at a quick rate please note this on your service request form.

The wood inspection software can provide automatic results for pole inspections and detailed measurement activity for wood products. These can be uploaded to three different devices per license.

Yes, we conduct a first short training via telephone or video call after you have bought a drill. You can also attend to one of our seminars. You can find more information at IML Seminars.

Our wood inspection drills are commonly used as a reinforcement for the VTA for tree inspections. The resistance drill is a favorite for arborists and tree specialists because it provides data on the internal state of the wood. A tree specialist is able to show measurements backing up their conclusion to save or remove a tree using the data collected from the resistance drills. They get this by drilling into any area of the tree including the trunk, branches or roots.

Many customers use the drill for pole inspections by conducting three drillings on the pole. First to determine the diameter for the WoodInspector software, second drilling into the base of the pole at an angle of about 30 degrees and then another drilling perpendicular to this at the base of the pole. This way the inspections are calculating the data below ground where there is a higher chance of decay. The WoodInspector software provides instant results of the drilling by determining if the pole is a pass, marginal or fail.

With the WoodInspector- software you will get a direct condition assessment of the wooden pole right after performing the measurements. Here, individually specified rot and cavity limit values of the timber branch to be inspected are included as criteria for the evaluation. To view more details visit the WoodInspector page.

Yes, you can take the information from PD/F Tools or WoodInspector and utilize it in your GIS or other related software.

The PD- and F-Series are available in different versions. The MD-Series is only available in one drilling depth.

  • IML-RESI PowerDrill-Series: 200mm – 1000mm
  • IML-RESI F-Series: 300mm – 500mm
  • IML-RESI MD-Series: 300m

The wood inspection drill measures the force of the needle turning through the wood product. For example, when the bit hits any soft decay the force on the graph will drop and if the needle hits a hard, brittle decay the graph will spike. If the bit runs through a cavity area the graph will drop measuring no resistance for the bit. The measurements are then collected on either a wax paper strip (F-Series) or electronically recorded for an instant upload (PD-Series).

With the F-Series drill the measurements are recorded on a wax paper strip. Typically users scan the wax paper strip into their report reinforcing their assessment of the wood. The PD-Series drill records the measurements automatically in digital form and can instantly upload these results to your computer via Bluetooth or USB cable. Software is available for your computer to analyze and organize your collected results.

Measurements can only be opened via the “Open measurement” button in PD-Tools/PD-Tools Pro. It is not possible to open an .rpg file directly.

All additional modules can also be retrofitted to your device. Either at our service centre or conveniently at your home with an activation code generated by us.

A test disc is worn out when the needle is assessed with the needle status “Worn out, replace needle!”. Wear marks/indentations are safe indications for a worn out test disc.

The test disk may be worn out. The test disc is a replaceable disc in the front adapter. If the needle is pulled through the test disc during the needle test, the needle is rated as bad. It is possible that the test disc is worn out. For this purpose, we offer exchangeable test discs and the appropriate tool.

This activates the automatic needle retraction. This is a protective mechanism that counteracts excessive bending of the needle. It is set to 5 cm by default. The retraction length can be adjusted under Control Panel > Automatic Needle Retraction.

! We recommend a retraction length between 5 – 10cm. If the retraction length is too long, the needle and the telescope can be damaged when the needle breaks!


– Active Bluetooth mode means the pairing is started by the drill. You must create a new connection in order to pair. To do this, you must find the computer on the side of the device and pair it.
– Passive Bluetooth mode means that the computer or the handheld initialises the pairing. To do this, you must search for and pair the Resi via the computer’s own Bluetooth manager. (This pairing variant is the most common pairing variant).


The Bluetooth must be turned on. And the correct mode must be selected for your device pairing. If there is still no connection, try out to update your Bluetooth driver. Instructions can be found under Instruction manuals & software downloads in the “Bluetooth Drivers” section”.

Control Panel > General > Rotate Display: NO

Now the rotation mode of the display is switched off.

A drill chuck should be replaced when irregular resistance is felt when turning by hand, or the rear “offset value” is over 400. (see illustration)

The needle wear depends on several factors. You will find an illustration of this in the maintenance instructions (page 14) enclosed with your machine.

Press the device against the object to be tested. When the safety button is pressed, press the red and black button simultaneously. The tilt indicator in the display now lights up green and the REL symbol appears in the upper right corner. The current unit orientation has thus been selected as reference plane 0°. To switch off the real time mode, return the unit to its original position and press the safety switch and the two buttons again, or switch the unit off and on again.


Press the red button for a long time > Tilt compensation: ON

Now the tilt compensation is switched on. If the drilling depth preselection is switched on, the machine will select the actual drilling depth according to the set diameter/radius and the current tilt angle. ! The TLT add-on module is required for this!

Remove the 45° adapter and detach the front adapter from the unit Now move the feed unit forward !SLOWLY! Guide the telescope by hand to avoid jamming the drilling needle in the telescope. When you reach the front end position, pull the telescope out of the unit. Now bend the broken drilling needle by 90° and hold it with the pliers for the manual needle change. Remove the needle. Insert the telescope in the front end position and then move back to insert a new needle.

If any problems or uncertainties arise during disassembly or reassembly, please contact our service department. We will be happy to assist you.

Your unit synchronises itself with the system time of your computer each time it is connected. The current time set in the computer is always used.

The individual feed rates can be assigned individually via the System controls > Feed rate menu. By deleting the individual values, individual feed rates can also be deleted completely from the “Quick selection”.

It is possible to choose between several drilling needle speeds in the Advanced View, equal to the feed rate

System Controls > Drilling Needle Speed > Mode: Advanced

The different steps can also be individually assigned different speeds.

There is the possibility of data recovery. This restores all data still present on the Resi. Provided they have not yet been overwritten. Control Panel > Data Recovery > YES

Make sure that the drilling depth preselection is switched off. If the number 2.0 appears on the display, the drilling depth preselection is set to 20mm. To deactivate it, press and hold the red button while the machine is switched on. Now the Drilling settings menu appears and you can switch the drilling depth preselection to OFF status.

Check whether the 45° adapter is correctly mounted and whether the symbol for the safety switch lights up in the display when pressed.

Press the red or black button instead of the navigation button for a longer period of time. If the device does not switch on again, contact the service. Switching on via the navigation button can be activated/deactivated in Control Panel > General > Navi Button Switch On Device.

To do this, you will probably need to update the USB drivers on your computer – you can obtain the necessary information and drivers from our customer service.

The standard scope of delivery includes 2 batteries (18 V, 5.0 Ah). These can be fully charged in approx. 30 minutes with the quick charger.

Do you have more questions?

Your question wasn't answered?
No problem, we will help you personally.

    Detailed information on handling user data can be found in our Privacy policy.