Calibration of U137, U235 & 237 Series Weight Indicators.
Date:141027 B01950 1(10)
Unisystem AB
Bergebyv. 24
Tel.:
0560-140 55
www.unisystem .se
685 34 TORSBY (Säte)
Fax:
0560-101 25
info@ unisystem .se
Index.
Page
1 Coarse gain, offset and response time. Keyboard functions at calibration. Calibration sequence.
Page
2 Calibration sequence.
Page
4 Calibration sequence.
Page
5 Calibration sequence. U2375 with tilt sensor. Restrictions for verified scales.
Page
6 Setpoints. Programmable serial output codes. Serial input.
Page
7 Transducer connector. U237 connector. U137 RS232 connector. Internal connectors.
Page
8 U2375 tilt transducer connector. Optional connectors.
Page
9 Precautions when installing! Flow measurement. Pictures.
Page 10 Pictures.
Coarse sensitivity (gain), offset and response time.
In order to make coarse adjustments of sensitivity, offset and low pass filter, the bottom panel must be removed
and the boards taken out. Be very careful with the flat cable to the front panel! All switches and jum pers are situated
on the main board behind the display board, under the shield. Normally these adjustments are not necessary.
The accuracy of the settings is better than 0.5% .
Input sensitivity, corresponding to 93700(0) AD-units:
Response tim e to 0.1% , optional resistors:
S2:
1,3
3
1
2
on
J15-16-17
Standard
J15-16-17
2.673
1.663
1.021
0.634
mV/V
410ms
R10, R15 removed.
2x4.99M
290ms
2x10M
2360ms
The offset is set by:
2x1.74M
206ms
2x4.99M
1180ms
JP10
3-6
5-6
4-5
1-4
2-5
on
2x715k
120ms
2x2.74M
648ms
JP11 off
0.000
0.314
0.410
0.508
0.821
mV/V
2x383k
75ms
2x1.74M
410ms
JP11 on -0.052
0.262
0.358
0.456
0.769
mV/V
2x169k
37ms
2x715k
200ms
The response time to 0.01% error is twice the time above.
The 3dB frequency in Hz is 1/(2.2 x the time above in seconds)
The following values are set at delivery: Sensitivity 2.673mV/V, offset -0.052mV/V and response time 410 ms.
Lower input sensitivity with no offset may be received by:
3.424mV/V for JP10 off, S2:1,3 on. Connect R11:12 to R11:13. Disconnect U11:8.
4.272mV/V for JP10 off, S2:1,3 on. Connect R11:6 to 11 and 12.. U12:1 to R11:10. Disconnect U11:8. (U2396)
U235
has a fixed offset of -0.069mV/V.
The sensitivity is 2.673m V/V but may be changed to 1.663m V/V (W5 cut off) or 1.021m V/V (W6 cut off).
There is a 3-pole filter with low ringing. The response time is 1.6 seconds or 0.5 seconds with S2:1, 2 and 3 on.
Keyboard functions at calibration.
The software calibration is performed via the serial input or the keyboard (U235 and older U2373 must have a
separate keyboard, U2395). The functions of the keys at calibration are as follows:
{ZERO}
Steps forward one position in the calibration sequence. Previous step is stored.
{TARE}
Steps back one position in the calibration sequence. Previous step is stored.
{NET/GROSS}
Selects the digit position of data. In sign position, the NET indicator blinks.
Switches between increment and decrement in Cs1 to 22. (Cs = Calibration step).
{COUNT}
Increments or decrements the digit value and changes sign.
{F} {ZERO}
Cs23-25. Gets the signals AD-value. {F} immediately after gets the old value back.
Cs31, 32. Sets the displayed AD-value to zero e.g. at 0° tilt for easier calculation.
{F} {TARE}
Extrapolates the AD-value in Cs25 from Cs23 and Cs24 when max weight is missing
{PRINT/TEST}
Prints the calibration sequence and program information.
{F} {F}
Returns to the AD-value (before Cs1). Skips change after {F} {ZERO} or {TARE}.
{F} {PRINT/TEST} {ZERO}
Enters preset values marked * below, when the AD-value is displayed e.g. after {F} {F}.
Calibration sequence.
The calibration switch S1 is located on the bottom panel. W hen S1 is switched on, the software calibration mode is
entered and the 6 digit internal AD-value is displayed. U137 and U235 only presents the 5 most significant digits for
the AD-value.
In the following calibration sequence, the functions and calibration may be changed.
W hen S1 is switched off, the indicator enters weighing mode. Restart the indicator to get all changes.
The calibration sequence is also entered without S1 by {F}{ZERO}, 3 successive times (from 001127). Cs 01 to 15
may be changed but not the calibration. The sequence is left by {F}{F}.
The display shows XX NN. XX is Cs(Calibration step) for 01 - 22, 28 and 29. NN is the chosen function code.
= code cannot be used together with any other = code in the same Cs.
+ code can be combined with any other + code and one = code in the Cs.
Add all + codes and the = code to get the number NN to enter in the Cs.
* means preset data according to the above. New separate indicators are delivered with these values.
Steps 23 - 27 and 30 - 32 have more sub steps according to below.
Not used steps, may be used for special functions, and NN = 0 must be chosen.
