Hydrostatic Level Probe HLP250C / HLP250S “Quality Matters” Features Any measurement range from 2 up to 20 m H2O Integrated internal overvoltage protection circuit Application The HLP250S and HLP250C probes are applicable to measure levels of liquids containing contaminants or suspensions. A typical use for this probe is the measurement of levels of liquid waste in intermediate pumping stations, fermentation chambers, settling tanks etc. Principles of operation, design The probe measures liquid levels, basing on a simple relationship between the height of the liquid column and the resulting hydrostatic pressure. The pressure measurement is carried out on the level of the separating diaphragm of the immersed probe and is related to atmospheric pressure through a capillary in the cable. The use of a special separator with a large uncovered diaphragm minimizes the metrological effect of sediment deposit on the diaphragm surface. This enables the probe long lifetime and proper work in contaminated media (even in the presence of abrasives, such as sand) and facilitates cleaning with a delicate stream of running water (washing with water under pressure may damage the probe). The active sensing element is a piezoresistant silicon sensor separated from the medium by an isolating diaphragm. The electronic amplifier, which works in combination with the sensor, and is meant to standardize the signal, is additionally equipped with an overvoltage protection circuit, which protects the probe from damage caused by induced interference from atmospheric discharges or from associated heavy current engineering appliances. Installation, method of use When lowered to the reference level, the probe may either hang freely on the cable or lie on the bottom of the tank. The cable with the capillary can be extended using a standard signal cable. For the cable connection a special SG cable hanger is recommended. The cable connection should be situated in a non-hermetically sealed box (the internal pressure inside the box should be equal to the atmospheric pressure), preventing water or other contaminants from getting into the capillary. The PP junction box is recommended For systems with long signal transmission lines, it is recommended the using of an additional UZ-2 overvoltage protection circuit in the form of a wall-mounted box which allows the cables connection. When the probe cable is being wound up, the minimum winding diameter should be 30cm and the cable should be protected from mechanical damage. If there is a possibility of turbulence in the tank (for example, because of the mixer operating mixers or a turbulent inflow), the probe should be installed inside a screening tube (e.g. made of PVC). The line hooked on the lifting handle can simplify the operation of the probe pulling out. Cleaning the probe diaphragm by mechanical means is strictly prohibited. Date 01-06-15 Specifications are subject to change without notice Web: www.pci-instruments.com | Email: [email protected] | Tel: +44 (0)17

Hydrostatic Level Probe HLP250C / HLP250S “Quality Matters” Technical data for the HLP250 level probe Measuring range Any measuring range 2 / 20 m H2O (the standard ranges 2.5, 4, 10 m H2O) Thermal compensation range 0 / 25°C - standard Medium temperature range -25 / 40°C - standard (0 / 75°C ETFE and PTFE version). Caution: The medium must no be allowed to freeze in the immediate vicinity of the probe Electrical parameters Output signal 4-20 mA, two wire transmission, Special version 0-10V three wire transmission Power supply 8 / 36 VDC (Ex: 9...28 VDC) TR version: 10,5/ 36 VDC (Ex: 10,5.28...