How multi range equipment is better than single range

There are two types of Measuring Equipment as per the measuring Range.

1.Multi Range 

2.Single Range

The multi range Power Meters are more accurate then the single range Power Meters.

Suppose we have two equipment one is multirange and an0ther is single range meter.

Both the equipment has 0.1%  accuracy.

Accuracy ± 0.1% of reading and ± 0.1% of range @ 50 Hz @ 25 ℃ +- 5 ℃

Sr

Standard V

Total Multi-Range / ErrorsTotal Single Range / Errors
1700.000 0.2%0.2%
2350.0000.2%0.3%
3175.0000.2%0.5%
487.00000.2%0.87%
543.00000.2%1.85%
621.00000.2%3.43%
710.00000.2%7.1%
85.000000.2%14.1%

Example-

Measuring 7 volt Multirange meter vs Single Range meter

Range is selected 10v in Multirange and Single Range is by default 700 V range.

Error = 0.1% of 10v = 0.01 v in Multirange

Error = 0.1% of 700v = 0.7 v in Single range

Multirange Meter will show 6.9993 to 7.0007 

Single Range Meter will show  6.3000 to 7.7000

Same as when measuring                       5.00000

Multi-Range meter may be show          4.99 to 5.01

Single range meter may be show         4.29 to 5.70

In the case of power analyzer the power error calculated as total voltage errors + total current errors + Phase errors

Our all Power Analyzers are Multi-range and Ranges mentioned is as below.

Voltage Range : 5V ,11V, 22V, 44V, 88V, 175V, 350V, 700V

Current Range : 0.6A, 1.2A, 2.5A, 5A, 10A, 20A, 40A, 80A

Benefits of having multirange Power Analyzer.

Suppose we have a transformer to test, Ratings 132/33 KV 20MVA.

We will perform Full Load Test on it.

For that we will short the secondary (33kv) side and apply voltage from primary side up to the rated current 175A is obtained.

Now we will apply 115KV to obtain the 175A in 20MVA Transformer, and our power analyzer can measure the maximum 80A and 700V. So that we need to connect CT & PT to measure the Current & Voltage.

We will use CT scaling 1:10 & PT scaling 1:200,

CT will convert 175 A in to 17.5A & PT will convert 115KV in to 575V.

Now as we have CT/PT Ratio Scaling Feature in our Power Analyzer it will show you result by considering the CT/PT Scaling, It means if you have entered the CT/PT scale then it will show you 175A & 115KV instead of 17.5A and 575V. (Same as Power Scaling is also given)

In our all models CT/PT ratio scaling range is (0.01 to 500)

This way we required to measure the small value of voltage and current when we use CT & PT, that time the multirange equipment will give accurate result.

Let take example,

I want to measure 10g weight.

I have two weight scale 

One weight scale capacity is 1kg and it is used in jewellery shops and Another one’s capacity is 100kg and it is used to measure large weight.

Both has same accuracy 0.1%.

The weight scale which is used in jewellery shop will be show accurate result because in 100kg weight scale the maximum error will be 0.1% = 0.1gm and in 1kg weight scale maximum error will be 0.1% = 0.001gm.

The range of equipment matters in measuring equipment.

Therefore we have given the multirange Power Analyzer so that the percentage errors can be exempted. 

That’s for standard manufacturers (Yokogawa, Hioki, Norma, Fluke and Zimmer) does not make single range power analyzer

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