IEC 60770-1 pdf download

IEC 60770-1 pdf download.Transmitters for use in industrial-process control systems – Part 1: Methods for performance evaluation
1 Scope and object
This part of IEC 60770 is applicable to transmitters which have either a standard analogue electric current output signal or a standard pneumatic output analogue signal in accordance with IEC 60381 -1 or IEC 60382. The tests detailed herein may be applied to transmitters which have other output signals, provided that due allowance is made for such differences. For the evaluation of the intelligent transmitters see IEC 60770-3. For certain types of transmitters where the sensor is an integral part, other specific IEC or ISO standards may need to be consulted (e.g. for chemical analysers, flowmeters, etc.) This standard is intended to specify uniform methods of test for the evaluation of the performance of transmitters with pneumatic or electric output signals. The methods of evaluation specified in this standard are intended for use by manufacturers to determine the performance of their products and by users or independent testing establish- ments to verify manufacturers’ performance specifications. The test conditions defined in this standard, for example the range of ambient temperatures and power supply, represent those which commonly arise in use. Consequently, the values specified herein should be used where no other values are specified by the manufacturer. The tests specified in this standard are not necessarily sufficient for instruments specifically designed for unusually arduous or safety related duties. Conversely, a restricted series of test may be suitable for instruments designed to perform within a more limited range of conditions. When a full evaluation in accordance with this standard is not required, those tests which are required shall be performed and the results reported in accordance with those parts of the standard which are relevant.
4 General conditions for tests
4.1 Overview For the purpose of this standard, the general test conditions (e.g. environmental test conditions, supply conditions, load conditions, mounting position, externally induced vibrations, external mechanical constraints, constancy of the operating conditions and settings, input variable quality, delivery of the transmitter, etc.) specified in IEC 61 298-1 apply, together with the additional information below. NOTE It is desirable that the closest communication should be maintained between the manufacturer and the evaluating body. The manufacturer’s specifications for the instrument should be taken into account when the test programme is being decided, and the manufacturer should be invited to comment on both the test programmes and the results. 4.2 Supply conditions For the two-wire transmitters, the normal supply voltage might be 24 V d.c. For pneumatic transmitters, the normal pressure supply might be 1 40 kPa (1 ,4 bar). Tolerances on supply conditions, as given in IEC 61 298-1 , are not applicable to transmitters with self-contained power supplies (e.g. battery-powered). The tolerance for battery-powered equipment shall be agreed. 4.3 Load conditions The value of the load to be used shall be agreed. A load of 250 Ω is a commonly used value for electrical transmitters. For pneumatic transmitters, unless otherwise specified, a test load consisting of an 8 m long rigid pipe with a 4 mm internal diameter, followed by a 20 cm 3 capacity (or more), shall be used. Care should be taken to ensure that pneumatic connections are leak-tight. 4.4 Input variable quality For transmitters that are to be evaluated with an integral sensor, the conditions and requirements for maintaining the quantities to be measured (physical/chemical) shall be properly stated (e.g. for flow transmitters, the fluid through the measuring device shall be that specified by the manufacturer.