The speed gauge for mine electric locomotives is designed to:
1.Measure the travelling speed of accumulator and trolley locomotives ;
2.Determine the trail;
3.Control motor currents of electric locomotive;
4.Control temperatures of electric locomotive motors;
5.Display the quantity of machine hours.
The speed gauge controls all above mentioned parameters of electric locomotive by means of external sensors (Table 2)
The sensors are mounted on the controllable units, indicating units in the cabin.
The speed gauge permissibility is ensured by encasing the electric parts, with the case withstanding explosion pressure from inside and eliminating transfer of explosion into environment according to State Standard of Ukraine 7114.
Technical characteristics (Table 1)
| Serial no. | Parameter designation | Unit of measure | Value |
| 1. | Determined speed | km/h | 0-25 |
| 2. | Trail | km | 0-9999 |
| 3. | Motor current 1 | А | 0-750 |
| 4. | Motor current 2 | А | 0-750 |
| 5. | Motor temperature 1 | 0С | 0-120 |
| 6. | Motor temperature 2 | 0С | 0-120 |
| 7. | Machine hours | 0-9999 | |
| 8. | Supply voltage range, | V | 50-200/24 |
| 9. | Power consumption | Wt | 5 |
| 10. | Mass | kg | 15 |
Components of the product (Table 2)
| Serial no. | Designation | Quantity, pcs | Explosion protection level and kind | Protection level | Purpose |
| 1. | Speed sensor | 1 | RV1V | IP66 | Formation of rectangular pulses, with frequency proportionate to the rotation speed of railway motor |
| 2. | Current sensor | 2 | RV1V | IP66 | Formation of voltage proportionate to motor current |
| 3. | Temperature sensor | 2 | RV1V | IP66 | Formation of voltage proportionate to motor temperature |
| 4. | Indicating unit | 1 | RV1V | IP66 | Displaying in digital form of all measured parameters |