If you set the wrong number of rotation pulses at the tracking analysis, the displayed rotation number (speed) is different from the actual number. Therefore, the order which should be primarily analyzed does not match the setting order. The data which is saved in TRC file (tracking data) or ORF file (DS-0250 data recording) cannot be changed, so to perform tracking analysis again by using this data, it is necessary to convert the order which should be primarily analyzed to fit in with the saved data.

 

The following is an example of analysis method for "Order which should be primarily analyzed: First order/ measurement range: 1200 r/min to 3600 r/min" after you read the TRC or ORF file which is measured in the wrong number of pulse setting such as 20 P/R instead of 30 P/R.

 

 

Operation procedures

Relationship between the measurement rotation number and actual rotation number

According to the following formula, the rotation speed is measured (displayed) as 1800 r/min which should be primarily displayed as 1200 r/min.

 

 

According to this, the measurement range is displayed as 1800 r/min to 5400 r/min even the actual range is 1200 r/min to 3600 r/min.

 

Conversion of the target order

The actual number of rotations (speed) is multiple of 20÷30 of the number of measurement rotations. Consider to this, the setting order can be obtained in the following formula.

 

Setting order=Target order × 20 ÷ 30 (Target order: Order which should be primarily analyzed.)

 

When the target order is first order, the setting order is;

 

Setting order=1 × 20 ÷ 30=0.67

 

So, set 0.67 ord to the Line setting of the tracking display setting.

 

In addition, please note that the number of rotations (speed) and order display of the reanalyzed data in the tracking display screen is still same as the recorded data.

 

How to perform the actual measurement from the wrong setting data

 

Click [Input] > [Tracking] in this order on the menu to open the tracking dialog, and set upper/lower limit of the rotation number (speed).

 

 

Click [Display] > [Tracking Display] in this order on the menu to open the Tracking Display dialog, and input the converted order of 0.67 (put check mark on Peak Search).

 

 

Measurement data example

The order of the X-axis and Y-axis are remained as the previous data, so it is necessary to convert and read. In addition, order of 0.67 is not in the resolution range, so it is displayed in the nearest range of 0.69.

 

 

[Supplement]

Consider first order in frequency.

 

• Wrong setting (20 P/R)

When the number of rotations (speed) is displayed in wrong value such as 1200 r/min, the first order will be measured in the wrong point. When 1200 r/min is displayed, the frequency of the first order can be obtained by the following formula;

 

1200 ÷ 60 ×First order=20 Hz

 

• Correct setting (30 P/R)

The correct number of rotations (speed) is 800 r/min when 1200 r/min is displayed, so the correct frequency of the first order can be obtained by the following formula;

 

00 ÷ 60 ×First order=Approx. 13.3 Hz

 

The first order which you should be primarily measured can be obtained as follows; 13.3 Hz: 20 Hz = x: first order; x is approx. 0.67 order. Please look at this order to obtain the correct result.