Transformer Oil Express Test Kit

Description

ТОЕТ
detects moisture in oil quickly and precisely – even in miniscule quantities.
Express test kits have been developed specifically to detect the amount of moisture in dielectric insulation oils, which is necessary for normal operation and timely maintenance of electric equipment.
The high precision and excellent long-term stability make this testing device an ideal solution for continuous monitoring of moisture in transformer oils.
The test kit is compact, reliable, simple to operate and multifunctional; it is the best choice for moisture measurement. The device also measures such parameters as water activity (aw), temperature (t), and calculates absolute water content in ppm. The device combines everything necessary for simple and comfortable operation: two digital displays to indicate sample temperature moisture content in ppm, a detachable sample container and two buttons: power and measurement.
The test kit combines a wide range of capabilities and economy. Changing a sample has never been easier: simply change the detachable sample container and press the measurement button to start!
Operation of the device includes:
1.
Pressing the POWER button; the power light comes on,
2.
Rinsing the container with the sample oil,
3.
Placement of the container and pressing of the TEST button.
A blue light is on during the test. After a brief time to stabilize sensor readings, the indicators display moisture content and temperature of the sample.
Industrial components are installed inside the device.
The IP protection of the kit allows to use it directly on site near the transformer. The device is equipped with heavy-duty anti-vandalism buttons, metal protection of the sensor, stabilizes power and integrated electric protections for high reliability and ruggedness. It is a true field tester for use even in adverse conditions.
Specifications
Range
0...1 aw
(
water activity
(aw))
Precision at
20 °C
±0.02 aw (0...0.9 aw) ±0.03 aw (0.9...1 aw)
Temperature measurement
Yes
Extra functionality
High precision
Sample temperature, °С
-40...80
Ambient temperature
, °С
-40...60
The content of water in oil can be described as absolute (ppm) or relative (aw).
- ppm is the ratio of moisture weight to oil weight;
- aw is the actual content of water expressed as a share of completely water-saturated oil.
An aw value of 0 corresponds to completely dehydrated oil, whereas aw=1 corresponds to completely saturated oil. The device measures aw with a capacitance sensor, which ensures excellent stability over long time with high resistance to contamination. The measured values are water (aw) and temperature (T). Using these values, the express test kit calculates the amount o water in ppm in mineral transformer oil. Calculation of moisture content for non-mineral transformer oil is only possible after loading the oil’s parameters into the unit.
Benefits
:
Compact, economical and functional
No PC required
The test kit does not require a computer, therefore there are no issues with data safety and network compatibility.
The accuracy statement includes the uncertainty of the factory calibration with an enhancement factor k=2 (2 x standard deviation). The accuracy was calculated in accordance with EA-4/02 and with regard to GUM (Guide to the Expression of Uncertainty in Measurement). Electromagnetic compatibility EN61326-1 and EN61326-2-3
.
TOET moisture measurement principle
Humidity measurement in oil similar to the humidity in the air, the water
content in an oil can be described by the absolute value in ppm or by the relative value aw: - ppm (mass of water / mass of oil) - aw (actual water content as fraction of the water content in the saturated oil) aw = 0 corresponds to water-free oil, while aw = 1 describes fully saturated oil. aw measurement with transmitter is based on the outstanding long term stability and resistance to pollution of the
sensor elements. The physical quantities measured are water activity aw and temperature T. With these quantities sensor calculates the water content (ppm) in mineral transformer oils. Calculation of water content in non-mineral transformer oils and lubrication oils can be accomplished by inputting specific parameters of the oil. The measured and the calculated values are available on two free scalable and configurable analogue outputs. The user can easily readjust or calibrate the transmitter by using either a simple procedure with the configuration software. The configuration software allows flexible and simple adjustment of the analogue outputs in accordance with the requirements.
The water activity describes the dissolved water against the saturation point at a given temperature. The water activity is measured directly as the dielectric polymer (the sensing polymer) is sensitive to moisture. The absolute water content is calculated in relation to the mathematics, which define the saturation curve. These parameters A, B define the pendency of the saturation curve. For mineral transformer oil general A and B parameters are know from the literature and are the default setting of transmitter.
Calibration for a specific oil is a laboratory procedure for determining the saturation curve of the oil. These parameters are used for setting up the moisture in oil sensor for correct calculation of the water content (ppm) out of the measured temperature and water activity (aw). Mineral transformer oils from different manufacturers are quite similar. So A and B parameters are the same for transformer oil.
For other oils the solubility parameters A and B have to be determined in a laboratory using Karl-Fischer method.