Digital Safety Ohms Meter

This is a special purpose instrument having full-scale range of 1.999, 19.99 or 199.9 Ohms, for the measurement of low value resistors. The unit is portable & operates on 9 volts battery. 3½ Digital Liquid Crystal Display, consuming very low power is used to indicate the measured value. The basic feature of unit is that even the measurement points are shorted externally the current flowing through the resistance to be measured is less than 2 m Amps thus making it safe to use in hazardous environments. In the case of overange the display indicates 1 in the most significant digit with all other digits going blank. Measurement accuracy does not depend on the battery
condition, is another feature of the instrument.

Time Synchronising System

The Time Synchronizing unit consists of GPS (Global Positioning System) along the data received through the Satellites. In order to get the correct data, at cold start the GPS unit will need to receive the data from Four (4) Satellites. Once it gets correct time, only three (3) satellites are enough normally for running the system in synchronism correctly. Time Synchronizing Unit, receives this data, decodes the timing signals and validates the same. The resolution of the timing Signals received from the GPS unit is 1 mSec.

The PC front-end software interrogates the unit, and collects the data either through RS232, or USB serial communication port. As the timing data, thus received through the satellite is same all over the world, it synchronizes all the PC System clocks.

The software has a facility to synchronize the clock every hour, every six hours, every day, at the on set of PC start, or At command, etc., through software settings.

The accuracy of the setting of the clock is
1 mSec. Maximum.

The unit can also be used to synchronize the System Clock of various field units like RTU, Wireless Transmitters, etc. used in a SCADA system.

System works on 230 Volts AC mains, or can be made to operate on 5V/12V/24 DC Voltage or any other voltage on demand.

Response Time Measurement Unit Of Temperature Sensor

The equipment measures the response time of the thermocouple or platinum resistance sensors, which is one of the critical parameters, in the case of temperature sensors. The range of the unit is 999.999 Seconds with 1 millisecond as resolution. A crystal controlled clock is used for measurement of time for better accuracy, stability and reliability. The continuous display of input is provided for monitoring purposes.

The unit is capable of accepting

• 0 – 40.00 mille Volts for Thermocouple inputs.
• 0 – 400.00 ohms for platinum resistance sensors.

The input - either thermocouple of RTD is selected by switch. The four wire method is used for measurement of RTD input; however three wire or two wire method can also be implemented.

The instrument measures the time between the two set points preset with the help of two sets of keyboard and alphanumeric display, and is stored in Battery Backed up RAM RTC.

The measurement can be performed either on UP-GOING or DOWN-COMING modes, selectable by data entry. Time count is started, when the input of the sensor under test, goes above the minimum setting and is stopped, when the input goes above the maximum setting in UP-GOING mode. Similarly time count starts when input comes below upper settings, and stops when it comes below lower settings in case of DOWN-COMING mode.

The special features such as error indications (with audible output) on wrong settings, invalid inputs and reserve polarity connection in case of thermocouple input, make the instrument safe and reliable.

The special Diagnostic software is provided to check the proper functioning of equipment. One can enter into diagnostic mode with the help of DIG switch provided at rear panel.

The indication is given on 20x4 Alphanumeric backlit display for time and input.

The equipment works on 230 +\- 10% Volts, 50 Hz, single phase AC mains and has size of 350 mm (W) x 140 mm (H) x 270 mm (D)