MR MSENSE DGA 2 - Device Field Calibration; Taking a Sample for Field Calibration

10 Maintenance
Messko GmbH 2020 71BA4001150/10 EN MSENSE
®
DGA 2/3
10.4 Device field calibration
The field calibration of the device gas analysis values serves to ensure the
correct measurement results:
▪ for aged insulating oils
▪ for modified oils (e.g. the addition of additives)
▪ for oils that do not satisfy the standards ASTMD3486-091, IEC60296 or
IEC60422.
A field calibration should be performed if the following conditions apply:
Condition CO H2 H2O
Deviation from lab-
oratory values
> 15% or 20ppm *) > 10% or 20ppm *) > 5ppm
Laboratory value > 50ppm > 50ppm > 5ppm
*) Evaluated in accordance with IEC60567 – Appendix E
A field calibration of a gas component with lower laboratory values is not rec-
ommended.
The correct values for a field calibration can only be guaranteed if the oil is
analyzed in the MESSKO GmbH laboratory or in a laboratory that special-
izes in gas analyses.
10.4.1 Taking a sample for field calibration
The following material is required for taking a sample:
▪ Oil extraction kit
▪ Oil waste container
▪ Cleaning cloths
▪ Sample extraction adapter
Taking a sample for a field calibration is only recommended if the following
conditions apply to the device:
Property Condition
Oil temperature T
oil
10°C < T
oil
< 90°C
Ambient temperature T
ambient
-20°C < T
ambient
< 60°C
To take an oil sample, proceed as follows:
1. Complete the sample information sheet included in the oil extraction kit.
When doing so, enter the current measured values under "MSENSE®
DGA adjustment" for:
– H2