THE HI504 from Hanna Instruments is innovative in the concept of pH and ORP control, offering elevated performance capabilities, rugged design and intelligent and advantageous use of tele-control technology.
Features of the HI504 include a sensor check system for pH/ORP electrodes, bi-directional RS485, digital transmitter input, programmable probe auto-cleaning cycle, event logging, 5VDC output for amplified probes, fail safe alarm system, programmable hold system, GSM SMS messaging of errors and system querying.
These features are only part of the instruments' extensive capabilities.
The sensor check system provides a continuous inspection of the probe condition and indicates an error in progress. The nature of the breakdown is reported, e.g., pH probe damaged, reference probe contaminated, dirty or blocked junction, reference junction not immersed in liquid, etc.
This information is displayed on the LCD of the instrument, can be viewed in real time through an RS485 link to a PC and can be sent directly to the operator's mobile phone as an SMS message.
The RS485 output permits the realisation of a network composed of a maximum of 32 instruments using a simple two-wire cable. The communication speed (between 1200 and 19,200bps) allows an RS485 network covering a maximum distance of 1km between the two instruments at the extremities of the network.
One or more units of the HI504 family can establish a network, or any other Hanna instrument that is supplied with an RS485 output can be incorporated, for example mV602, pH502, HI700.
The entire network can be managed by the HI92500 Windows-based software using a simple wire connection or a traditional modem. The program permits the operator to select any instrument from the network and visualise and record the data.
The digital transmitter input permits a connection between the pH/ORP electrode and the HI504 of up to 1000 metres. The data transmitted can be selected as either pH and temperature, or mV and temperature. The HI504 also has an input for an analogue transmitter.
Heavy-duty applications often require an almost continuous maintenance of the probe. In a brief period, elements such as suspended solids, fat, oils, pigments, and micro-organisms, can deposit and soil the glass bulb of a pH probe, the sensor of an ORP probe, or the reference junction of both.
The cleaning function permits the control of these inconveniences by programming one or more wash cycles of the probe. Two cleaning cycles are available; simple cleaning is a wash with a single element, e.g., water or detergent, while advanced cleaning uses both elements.
A delay can be programmed between the wash cycles and the resumption of readings to ensure the probe has adjusted completely to operating conditions after being exposed to cleaning elements at different pH values.
It is possible to view the sequence of the last 100 events that have occurred; errors, calibrations, variations of the system set up, cleaning cycles, etc.
A ±5V dc output on the instrument rear allows the use of amplified industrial probes that require an outside power supply, for example HI1004/5.
The 'hold' function permits the user to deactivate the regulating action of the instrument for periods of time that can be pre-programmed. Hold periods can be used to correspond to programmed operations such as plant maintenance, probe cleaning and calibration.
In short, HI504 is a versatile instrument that can be used either as a pH regulator or as an ORP regulator.
The universal BNC connector permits the use of whatever type of industrial probe chosen for a specific application.