Assembly ends

Glass-fibre reinforced polyamide based (PA) technopolymer, black colour.

Support

Aluminium in natural colour.

Graduated contrast screen

White lacquered aluminium. It can be taken out before assembly to allow the insertion of level lines or words.

Bracket with sensors

Watertight glass-fibre reinforced polyamide based (PA) technopolymer, black colour.

Swivelling connector

With built-in cable gland and contact holder. Front or axial output (high or low) ensuring protection against water sprays (protection class IP 65 according to table EN 60529 table-).

Standard executions

See configuration table.

 

Technical data

In laboratory tests carried out for a relatively limited time with the following liquids at a temperature of 23° C: mineral oil type CB68 (according to ISO 3498) for HCK, mineral oil type CB68 (according to ISO 3498) water or water/glycol-based solutions ( 50%) for HCK-GL, the resistance values were much higher than 35 bar.

For use with other fluids and under different pressure and temperature conditions, please contact ELESA Technical Department.

In any case we suggest to verify the suitability of the product under the actual working conditions.

Functioning of the MAX temperature sensor

• NO: the electrical contact closes when the pre-set temperature is reached at 80°C.
• NC: the electrical contact opens when the pre-set temperature at 80°C is reached.

Functioning of the temperature electrical probe

The working principle of the temperature probe is to measure the variation of resistance of a platinum element: 100 ohm = 0°C, 138.4 ohm = 100°C.

The function between temperature (T) and resistance (R) is approximately linear over a small temperature range: for example, if you assume that it is linear over the 0° to 100°C range, the error at 50°C is 0.4°C.

For precision measurement, it is necessary to linearise the resistance to give an accurate temperature. The most recent definition of the function between resistance and temperature is International Temperature Standard 90 (ITS-90). The function between resistance and temperature, obtained in laboratory tests, measuring directly the resistance value on the contacts is shown in the graph. We suggest, anyway, to set the system in order to compensate both heat dissipation and cable resistance.

 

A 1°C temperature change will cause a 0.384 ohm change in resistance, so even a small error in measurement of the resistance (for example, the resistance of the wires leading to the sensor) can cause a large error in the measurement of the temperature.

Because of the low signal levels, it is important to keep any cables away from electric cables, motors, switchgear and other devices that may emit magnetic or electrical noise. Using screened cable, with the screen grounded at one end, may help to reduce interference.

When using long cables, it is necessary to check that the measuring equipment is able to handle the cable resistance.

Special executions on request

• Column level window in transparent methylmatacrylate (PMMA) for max 70°C use.
• Polyamide based technopolymer float (from HCK.127) red colour.
• NBR float (from HCK.176) black colour with AISI 316 stainless steel spiral for special executions, viscous liquids, high temperatures.
• Indicators with level visibility (e) up to 1429 mm and fixing holes with hole centre distance (f) up to 1500 mm.
• Packing rings in special material depending on the customer's needs.
• Special screw with nickel-plated brass tap to be fitted to the lower assembly end for any maintenance operation requiring the indicator exclusion.

Connector assembly instructions

1. Remove the connector from the indicator by unscrewing the set screw placed on the connector, take the contact holders out and loosen the cable gland.
2. See Fig.3 to proceed with the wiring according to the chosen product.
3. Assemble by pressing the contact holder into the connector in the required position.
4. Screw the connectors to the indicator and then tighten the cable glands.