Why is my KM330/340 displaying ‘OL’?

If you own a KM330 Industrial Thermometer, or a KM340 Industrial Thermometer with twin inputs, and it is displaying ‘OL’ on the LCD Screen, as shown below, this could be for a couple of reasons.



The ‘OL’ message will appear if your KM330/KM340 Industrial Thermometer is turned on without a Probe connected via the device’s sub-miniature connection.

If a suitable probe has been connected via the sub-miniature connection on the front of the device and the ‘OL’ error is still being displayed, then this can indicate a fault with the connected probe.

In this instance we would recommend that the probe in question is disconnected from the device and a new or alternate probe is connected instead.

Should the ‘OL’ error message persist, despite alternate probes being connected and tried, then the Thermometer(s) in question will need to be returned to our Service Department for repair.

Please click here for a copy of the Service Form which you will need to complete and include with any Thermometer(s) that you wish to return to the Service Department of Comark Instruments.