Ohmic sensing is a critical component when piercing and cutting thin plate with plasma. The issue is that the thin plate will flex when the torch touches and then flexes back up when it moves up. The result is inaccurate transfer, pierce and cutting heights. Ohmic sensing is when the system can tell when it’s getting close to the plate by measuring the resistance between the torch tip and the material. As the resistance goes down (< 1 MOhm) the system knows the torch is getting close to the plate. The result is you don’t flex the plate or dimple the plate if the material is really thin.

Specification

• Power - 12V DC, 0.1 A, with integrated reverse voltage protection
• Over Voltage protection 15 V
• Sensing range - (0 - 1) MOhm
• Output - isolated Normal Close relay contact
• Life of used relay with a capacity of 12V/10mA - 1*10⁸ ops. minimum
• Ability to adjusting the ohmic sensor sensitivity
• Ability to eliminate HV/HF ionizing voltage

Ohmic sensing is very easy to accomplish with normal air plasma system, the issue is the Arc Start on high frequency systems.

Neuron Ohmic sensor has high protection and ability to eliminate HV/HF ionizing voltage. Ohmic sensor may be connected to torch shield or direct to torch nozzle.

Note:

Always use the Ohmic sensor with a backup sensing system like FloatHead (mechanical Touch-off) that will stop down motion or magnetic torch holder if the sensor fails to work. This can happen on dirty, oily, rusty or painted metal. Keep the tip of the nozzle on your torch clean and free from trash and slag.

Be aware that since electrical contact is required. The plate must not be coated or covered in non-conductive material. Please note that if you use a water table, the torch shield gas tends to splash the water around and the result is that it gets on the torch, which closes the Ohmic circuit or that the torch will do down into a puddle of water on the plate, which could result in a miss cut. More care needs to be taken when using ohmic sensing over water.

Ohmic Sensor Output