"ESCORT-TD" Fuel level unit
Escort-TD fuel level unit or capacitive level gauge is a high-precision measuring instrument designed by Escort Group of Companies to measure the level of light petroleum products in any reservoirs (storage tanks) with maximum fill height of one and a half meter.
The sensors are designed and manufactured to meet individual requirements of customer as to the fill level, for instance, Escort-TD fuel level units are widely used in underground storage bunkers at petrol stations, railway tanks and other high-capacity containers. The fuel level unit is used to identify the level of light petroleum products in systems that measure and control the amount of fuel and lubricants in a variety of containers.
The area of application of fuel level units covers motor-vehicles and tractors. They are used as fuel gauges in various industries to control the level of any light products in any tanks and storage reservoirs.
Escort-TD fuel level unit can be installed instead of the standard fuel gauge with the similar flange which is mounted in a manner normally used for float automotive fuel level sensors in the CIS country.
The fuel level unit converts the level into a digital code, and transmits it via RS-485 interface. The unit has an analog signal output for connection to the needle level indicator and output for indication of emergency level of residual fuel.
Installation of the Fuel Level Sensor in Tank
The mounting dimensions of the fuel level unit allow its installation in regular places instead of existing “float sensors” with preservation of the functions of emergency level of residual fuel indicator and lamp (LED). Such installation of the fuel level unit is suitable for vehicles operated on a level terrene. In other cases, it is necessary to drill a hole in the geometric center of tank, install the fuel level unit and to secure it with the screws provided.
Typically, the tanks have partitions, and, therefore, first it is necessary to drill a 3 mm hole at the designated installation location, and then to guide a hook through the hole to check whether there are any partitions within 20 mm.
If there is no partition, drill a 27-32 mm hole in the tank with the use of a metal-cutter head. If partition is close, the hole is drilled at a distance from the partition, and is used a mounting hole. In any case, field testing of the results is required, because the monitoring system software often enables to “smooth over” the data, and this may be sufficient for the operator.
Modes of Operation
In this mode the unit waits for a request from external device. 2...3 msec after receiving the request, the transmitter sends a response that includes information on the level and temperature. It deals only with the requests in which the network (IP) address is identical to the address stored in the transmitter memory.
In this mode the unit continuously generates the frequency corresponding to the measured level. Zero level corresponds to the frequency of 300 Hz. Maximum level corresponds 1323 Hz. In case of incorrect setting of maximum level the frequency may be higher or lower than 1323 Hz. Generation of frequency 60-90 seconds after the power is turned on.
In this mode the unit generates analog voltage corresponding to the measured level. Zero level corresponds to 0.1 V. The maximum level (3) corresponds to 4.9 V. In case of incorrect setting of maximum level the voltage can be limited to 4.9V.
In this mode the unit generates a 50 Hz pulse burst. The number of pulses in the burst corresponds to the measured level. Zero level corresponds to 2-pulse burst, and maximum level corresponds to 1025 pulses. Time span between bursts is 62 seconds. The first burst is generated 60-90 seconds after the power is turned on.
Escort-TD Fuel Level Unit:
- sends a signal to the regular fuel gauge;
- sends a signal of emergency level of residual fuel;
- can be re-flashed in field;
- can provide remote change of level;
- can be protected with a password, if you like;
- is available in four standard versions L600, L750, L1000 and L1500, and can be extended up to 6 m;
- can be up to 15 cm long upon cutting;
- has explosion safety and metrology certificates.
Peculiarities of Fuel Level Unit Connection
The fuel level units are supplied with a standard cable 70 cm long. The cable can be extended with the use of PVA-4x0.75 wire laid in a corrugated tube. If outputs of emergency level of residual fuel indicator and lamp are used, they can be connected directly to regular wires, if the connector is removed from the regular gauge and securely sealed. All wire connections outside the driver cabin must be securely sealed to preclude any contact between water and copper. For example, apply a layer of sealant on the point of the cable connection, put a thermal contraction tube (heat shrink) of appropriate size and let it shrink by pressing the excess sealant out.
Installation of Two Fuel Level Units in the Same Tank
To improve the accuracy of readings and reduce their fluctuations it is allowed to install two fuel level units in the same tank. The fuel level units are installed on length of 1/3 and 2/3 of the tank along its midline. It is mainly used in the tanks with a capacity over 600 liters and usually in RS-485 mode.
|Measured products||Gasoline, diesel fuel|
|Explosive mixtures according to GOST R 51330.11||Category IIA, IIB, Group T1…T6|
|Protocol of digital output signal||RS-485 19200 bps|
|Resolution of digital output signal||0,1%|
|Resolution of analog output||0,25%|
|Frequency signal range||300 ... 1300 Hz|
|Level indicator output resistance||0...110 Ohm ±10%|
|Emergency level of residual fuel||10% ±2%|
|Measurement accuracy in the working area, at least||1%|
|Linearity of characteristics, at least||1%|
|Ignition/explosion protection - intrinsically safe circuit level||«iа»|
|Ignition/explosion protection marking||0ExiаIIВТ6 Х|
|Degree of shell protection according to GOST 14254||IP67|
|Protection against electrical shock according to GOST 12.2.007.0||class III|
|Rated supply voltage||9...36 V|
|Consumption current, maximum||30 mA|
|Operating conditions - ambient temperature, °C||- 40...+50 °C|
|Operating conditions - atmospheric pressure, kPa||from 84 to 106,7|
|Measuring part length||500, 1000, 1500 mm|
|Dimensions , maximum||540х80х80 mm|
|Weight, maximum||0,5 kg|