Products:
SPECIFICATIONS
MODEL | MERLIN–13 |
Microbolometer | |
Resolution (pixels) | 256×192 |
Pixel size (μm) | 12 |
NEDT (mk) | ≤ 50 |
Frame refresh rate (Hz) | 50 |
Optical Specifications | |
Objective Lens (mm) | 13 |
Field of view (degree) | 13.5×10.1 |
Magnification (x) | 1× |
Detection range (m) | (Target size: 1.7mx0.5m, P(n)=99%) |
675 |
Display | |
Type | 0.39“ OLED |
Resolution (pixels) | 1,024×768 |
Operational Specifications | |
Battery type | CR123 (3.7V) ×1 |
Power consumption (mW) | About 800 |
Max. battery life (t=25°C)/(h) | ≤3.5 |
Operation temperature (°C) | -20 ~ +50 |
IP Rating | IP67 |
Dimension (mm) | 79×52×46 |
Weight (without battery) | (g) | ≤140 |
USB Type | Type-C |
Eyepiece Interface | M30×1.0 |
COMPONENTS
- Objective Lens
- Power (P) Button
- USB-C Interface
- Menu (M) Button
- Battery Compartment
- Eyepiece Locking Ring
- Eyepiece Interface

Liemke Merlin-13 Thermal Imaging Clip-On Instruction Manual
BATTERY INSTALLATION
- Remove the battery cap by unscrewing it counter clockwise
- Insert a CR123 with positive pole inwards
- Place battery cap onto the battery compartment and screw clockwise until tight
MOUNTING THE MERLIN-13 ON A RIFLESCOPE
Before installing the MERLIN-13 onto your Riflescope, the following preparations should be made:
- Select a clip-on adapter matching the outside diameter of the objective tube of your riflescope.
- If necessary, use a thread adapter that matches the thread interface on the MERLIN-13 and that of the clip-on adapter.

Liemke Merlin-13 Thermal Imaging Clip-On Instruction Manual
Installation
- Install the threaded adapter insert (8) to the MERLIN-13 by rotating clockwise along the thread.
- Rotate the eyepiece locking ring (6) counterclockwise to lock the adapter insert (8).
- Install the threaded insert (8) fully into the clip-on adapter (9).
- For mounting the clip-on adapter (9) on the riflescope, please observe the instructions for use of the manufacturer of the clip-on adapter.
MENU / STATUS BAR ICONS

Liemke Merlin-13 Thermal Imaging Clip-On Instruction Manual
OPERATIONS
Switch On / Off
- Press and hold the P button (2) to turn on the device. Waiting for 3 seconds to enter the home interface.
- Press and hold the P button (2) until the shutdown countdown is 0, release the button to turn off the device.

Liemke Merlin-13 Thermal Imaging Clip-On Instruction Manual
Standby Mode
- Press and hold P button (2) until the countdown appears, release the button within 3s countdown to active the standby mode.
- Short press P button (2) again to exit standby mode.
Status Bar
In the home interface, there are system information hints at the bottom of the screen including: Palette, Screen Brightness, Calibration mode, Battery status etc.
6.4 Calibration
- In the home interface, short press the P button (2) for shutter calibration.
6.5 Image Movement
- In home interface, press and hold the P button (2) and M button (4) to enter into the image movement interface.
- The movement distance and direction on X & Y axis appear on the interface.
- Short press P button (2) to move upward one pixel.
- Long press P button (2) to move upward ten pixels.
- Press and hold P button (2) constantly to move upward continuously.
- Press the M button (4) to move downward, and the adjustment

Liemke Merlin-13 Thermal Imaging Clip-On Instruction Manual
- Press P button (2) and M button (4) simultaneously to switch the movement directions.
- While switched to horizontal movement, press P button (2) to move towards left and M button (4) to move towards right. Movement method is same as vertical on Y-axis.
- Long press the P button 2) and M button (4) simultaneously to save calibration data. Once saved, the device will exit this interface after 2s.
Shortcut Menu
In the home interface, short press the M button (4) to enter shortcut menu. Options in Shortcut menu are as follows: Palette - Screen Brightness – Calibration – Exit.
- Palette: press P button (2) briefly to switch between White Hot - Black Hot - Red Hot - Pseudo Colour.
- Screen Brightness: Press P button (2) briefly to adjust the screen brightness among four levels.
- Calibration: short press P button (2) to switch between Automatic (A) mode and Manual (M) mode.
6.7 USB-C-Mode
- In the home interface, while connected with a USB-C cable, press and hold the M button (4) and meanwhile quickly press P button (2) five times to activate USB-C mode for updating firmware.
- Repeat previous steps or plug out USB cable to exit USB-C mode.
MAINTENANCE
Maintenance should be carried out at least twice a year and consist of the following actions.
- Wipe the external surfaces of metal and plastic parts free of dust and dirt with a cotton cloth. Silicone grease may be used for this.
- Clean the electrical contacts of the unit using a non-greasy organic solvent.
- Check the glass surfaces of the eyepiece and the lens. If necessary, remove dust and sand from the lenses (preferably using a non-contact method). Cleaning of the external surfaces of the optics should be done with substances designed specially for this purpose.