Some standard content:
Verification regulations for universal proportional arm bridge
JJG485—1987
Verification regulations for universal proportional arm bridge
Verification regulations for universal proportional arm bridge
JJG4851987
This regulation was approved by the national and local authorities on March 9, 1927, and will be implemented from January 9, 1988. Responsible unit: China Testing Technology Research Institute Drafting unit: China Testing Technology Research Institute This regulation is subject to the interpretation of the technical department and the starting unit. The main drafter of this regulation:
Sang Guangying (National Testing Technology Research Institute)
Technical requirements…
Verification items.
Verification method
Determination of the results and the period of verification
Verification regulation of universal ratio bridge
This regulation is applicable to the verification of the newly produced, repaired and repaired current-carrying resistor ratio bridge (hereinafter referred to as the standard ratio bridge?).
A method
The ratio of the ratio of the measured value to the standard voltage can be arbitrarily changed by a certain ratio. The universal ratio bridge can accurately determine the ratio of the measured value to the standard voltage. To carry out non-decade resistance, resistance box and seven-digit meter and other DC output and core resistance ratio measurement, the low-power proportional circuit diagram is shown in Figure 1: 1
Figure 1 Universal proportional bridge circuit diagram
-—Electricity
:? One by one: one power supply science
The example of the universal bridge ratio is equivalent to two very fine scales, the total resistance is constant sliding line resistance, the torque moving contact damages the two resistance groups at the bottom of the universal proportional flash two proportional resistors, the left side is the measuring mother disk, the name is called the external compensation disk, move the measuring function R. Then calculate:
Formula +: RI, R, R. and R.
1 Appearance epidemic ring
R-RIRN||t t||Reverse selector switch can be used in 1, 2.34, and can be used as the scale indication of universal proportional electrolytic analysis.
Secondary technology
1.1 The chrome plate or outer clasp of the universal proportional electrolytic bridge should indicate: 1.1.1 Product name, model and output number: [.1.2 Manufacturing unit or trademark;
1.1.3 Effective range and grade index;
, the "scale" refers to the reverse current of the power-off source, these currents refer to the same cooperative area, the pregnancy period method, the period, 5:0
1.1.4 Standard excitation and nominal use range 1.1.5 Test industry;
1.1.6 Use position (the position without position symbol table can be used as the intended position). 1 .2 Universal current bridge panel 1. The switch and load should be clearly marked with functions and symbols, 2. The grade index of the bridge, the standard temperature and relative humidity range, the standard temperature and relative humidity range! The provisions of
3 Universal ratio negative arm bridge in nominal use of mild and wet domestic, out of your standard conditions to the special use conditions of the allowable difference point exceeds the provisions of Table 1,
4 Universal ratio bridge measurement panel if the total resistance change error should not exceed the corresponding equal payment index. Table 1
Equal wrinkle estimation number
Scientific integral record
Standard acceptance
, allowable load to allowable fraud technology benefits of the self-score length: H
+0 -60
4n ·Fal
Nominal use to allowable deviation
Tolerance
25 -·75
25 75
5 When the universal proportional bridge is measuring the resistance of the panel, two additional inductors should be installed in the two arms of the bridge, and their values are: 0, 10N
6 Under standard conditions, the insulation resistance between the universal proportional circuit and any conductive component that is not electrically connected to the circuit should not be less than 5M, and the deviation caused by any terminal and external or large-scale connection should not exceed 10% of the basic deviation
7 The voltage between the proportional arm and the external or total conductive components that are not electrically connected to the circuit should be able to withstand the actual positive voltage of 500V ± 10% of the AC monthly voltage with a rate of 45~65H for 1min. Three verification conditions
B When the universal proportional bridge is used to correct the basic error of the measuring panel, the result is as shown in the table! The tests on the insulation resistance and voltage of the 9-arm bridge line are carried out under the specified standard temperature and relative humidity, and are carried out under the specified nominal operating humidity and relative humidity in Table 1.
10 The total uncertainty of the calibration universal proportional bridge shall not exceed 10.1 In the specified device, the error caused by the measuring instrument shall not exceed 1/10 of the index of the universal proportional bridge being tested. 10.2 In the calibration device, the error caused by insufficient calibration accuracy shall not exceed 1/10 of the index of the universal proportional bridge being tested.
18.3 In the calibration device, the error caused by other factors (including thermal potential variation, electric shock variation, etc.) shall not exceed 10.10 of the electrostatic conductivity index to be tested. 10.4 Under the condition of ensuring the specified total uncertainty, other error distribution methods are allowed: 11 The measuring instrument of the absolute voltage group shall have a measurement error less than 30%. 12 The commercial test bench used for the output test should have sufficient output capacity (maximum "D.25VA) and annual voltage adjustment of 31:
Four verification items
13 The universal proportional bridge is connected to the original H at the bottom and the bottom is connected to the original H at the bottom. Table 2 is the original verification item. The external must be corrected
Repair the circuit
Proper test position
Male identification difference
When leaving the factory
Note: "+", "—indicates danger
Screen product
Five verification methods
1 + External inspection
The mark on the nameplate of the universal proportional bridge should meet the technical requirements.
For the newly produced universal bridge, the components must be intact, and the universal bridge after use and repair must be in good condition. If there are any defects that seriously affect the performance of the bridge, they should be re-calibrated after repair: 15 Circuit inspection
Use the universal bridge proportional transformer with a meter. If any abnormality is found, find out the reason and re-calibrate after repair.
16 Final voltage measurement and test
16.1 Use a high resistance meter or single-edge current monitor to measure. If it is found that the insulation resistance cannot meet the requirements, find out the reason and re-calibrate after repair.
1G.2 Insulation resistance test: If the outer casing of the universal proportional ammeter is grounded (the outer element of the galvanometer is made of insulating material, place the calibrated metal plate on the gold mesh plate and then press the metal plate to the ground), connect the measuring limit of the effective range of the galvanometer to the standard end and the material under test with a nominal resistance, and do not switch it on 2 or 3. Adjust the universal proportional ammeter to make it balanced (the effectiveness of the tester should not be less than 1rm/5), then connect the other outlet wires to the grounded terminals and observe the deflection of the galvanometer. If all terminals are tested, If the error represented by the deflection number of the galvanometer is no more than 1/8 of the insulation grade index of the switchgear, the insulation resistance of the bridge is considered to be qualified. The test includes: 17 voltage test
Connect all the common power lines of the universal bridge circuit and connect them to the output of the test bench before the test. The other end is connected to the ground terminal of the test inch. The test voltage is steadily increased to the specified voltage at a rate of 100V/s. After 1 minute of voltage withstand test, if there is no breakdown or arcing, the voltage test is considered to be qualified. Otherwise, it is unqualified. Then the voltage is steadily reduced to the rate.
18 Universal ratio bridge error verification The basic error of the universal ratio bridge includes two items: one is the linearity error of the full-scale station (including the non-adjacent plate\ gate: 1" ratio error, and the other is the short-circuit resistance variation of the compensation plate method. 18.1 Verification of the linearity error of the compensation plate
18.1. Use the dial unit to verify the linearity error of the universal ratio bridge. The universal ratio is a real-time, unitless scale. In the verification of the linearity error of the measurement unit, any measurement unit can be selected. The unit of this two-way total universal ratio bridge is 1 of the average step value of the maximum scale of this bridge, that is, 1200 of the sum of the minimum step values of the second scale. This value is called the "scale unit". Using this scale unit to verify the linearity error of the universal ratio bridge is very simple: 1B.1.2. There are six methods for measuring the linearity error of the measuring disk: one is the calibration method, the other is the calibration method. The calibration method is selected based on the calibration ratio of the bridge grade gain number. 3
Leading paragraph: 9]
(1) Monitoring body calibration method
Receiving step method
Love to identify the ground installation
Investigation to ten generations of stations
Equal frequency sweep products
Make a design change certificate and select 1 and in the substitution method
Use current ratio light instrument potentiometer to calibrate the universal proportional kidney electric protection of the basic state error of the medical pain confirmation tour, the measurement panel residual error and compensation (total ugly error) are combined into the error comprehensive measurement method, and a calibration method can be specified and the reason for the calibration method is the original circuit diagram of the universal proportional arm electric measure. Standardized female step
H. Figure 3 will be controlled by the universal: Example back bridge rolling people my way. Preset Rs=430, make Ig=1-mA: please set the current comparator potentiometer to positive working state. b. Set the indication rate of the first measuring plate of the energy comparator bridge to 2, and the rest of the plates to zero: the current comparator potentiometer is set to 20 on the ×1 range, and the rest of the plates are set to zero, and adjust the R current comparator potentiometer to balance
. Set the indication values of the current comparator potentiometer and the universal comparator to the same, and the current comparator potentiometer measures the zero voltage of the energy comparator bridge measuring plate.
d. Then the energy ratio is set carefully by the folded tube plate FY
Shi Hanyuan
because 2 electric through batch comparison instrument potential meter overall control universal ratio meter electric correction principle line level
R one group not, - want to replace, once the rule is verified: J, steam migration of the original energy bone electric sample
20: the rest of the plate is zero: the current comparator has been the first plate of the potential difference Chen 20, the rest of the mils are unchanged, the return section also the comparator potential difference meter secondary fast industry plate to make the common street. e. Repeat steps c and d, straight stem two voltage difference is 2V until the meter calibration
heart with giant classics and standard chemical test current ratio ampere this meter, the medical plate medical file of the measurement base energy balance increase edge bridge encounter plate health all the quiet. Start each month until the maximum indication is reached. After each disk is observed, return to the quarter and record the indication when it is averaged again as
. Only in this way can the indication of each base disk be more accurate (expressed in degrees) than the standard electrical scale; after each year, subtract the indication of each measuring disk from the nominal indication of the measuring material, that is:
In the formula: the positive value of the 1st indication of the first measuring disk: the half-balanced indication measured on the potentiometer of the ammeter; [
, the 1st measuring disk: the 1st The nominal value of the indication; First, when measuring the indication of the electric disk, the current is compared with the level indication measured on the differential meter (2)
\, During the inspection and calibration process, the current change of the current comparator and potentiometer should be checked at any time. If the error caused by the change does not exceed 1/1 of the index of the inspected proportional correction, it should be re-standardized (decimal substitution method
1, when the decimal disk is replaced
, the ten step-value resistors of the next disk are replaced with each step-value resistor of the previous disk on the bridge device for comparison. Finally, each 1 g-2a of the disk is replaced by a
The new
diagram 31 is the principle circuit of the universal proportional bridge. The step value of the circuit is determined by the deviation of the internal galvanometer. As long as the ten step value resistors of the second disk take 1/20 of the total resistance of the first disk, the actual step value of the entire type of disk can be expressed in units of degrees by calculation. The principle circuit of the universal proportional bridge is shown in Figure 3. The circuit is connected according to Figure 3, and the parameters of the selected pole are: R=R=5—t is used for t, R—ratio 10n, R, =Rx=2121.66Q, ZX54 is set to 2111.11, ZX35:R, micro-communication department: ZX54-Please use \5 55, C2/33 all measuring disks are set to zero. : 2X5 25 electric: 3.3
sink ratio tube bridge; K-outflow reversing switch: upper straight electric lake: (a control meter
b. Turn on the power, adjust R. Make the bridge balance, J33 the first disk is set to 1, the other disks are set to the same, 2X54×1002 disk indication value retreats, the other disks are set to ZX35 to make the bridge flat, record the indication of each disk of 2X35 (for the first information of the test, it should be captured) as X54 remains unchanged, Q[33 the first disk indication value retreats to quarter, the second disk value advances from zero to 10, adjust 35 to make the electric folding, record the indication of each disk of 2X35. Steps and d realize the first step resistance value R of the first disk, and the comparison with the tenth step value of the second disk! The difference is:
SR! -bf -nl or n =Sr -!
5, the first plate of 933 is advanced to 2, the second plate is retreated to the fourth, the value of 2X54×1002 plate is retreated to 1, the remainder is unchanged, the 2X35 is adjusted to balance the electricity, the value of each plate of 7X35 is recorded as 42, 1.2X54 is kept unchanged, the 133-th adjustment is adjusted to 1, the second plate is stopped at 10, and the 7X35 is used to balance the electricity, and the value of each plate of 2X35 is calculated as 62, and the first plate and the second plate are compared with the second plate. The recommended value is:
According to this method, we get:
Sr! ia,RI-
mR! -6! -a! or R! -ZR! +A!
In the formula:! The first plate: the first step current positive value and the second plate: ten step delay compensation value: R
-the first plate, the next current:
-the second plate | step current sequence value
Similarly, for the north plate:
the first plate; the reverse resistance value and the +1st plate ten step current value are also selected appropriately: the difference between the first and the +1st plate, the required step current value: -1st, ten step current avoidance value,
g.J33 can be calibrated by the current meter method, and the last plate can change all the indications of Q133 to make the current detection deflect by 100 grids, and record the step resistance. When the value changes, the number of grids of the current is changed, and the resistance after each measurement is calculated as:
Where: Ri-
the last step current value;
one disk after lightness·one step current,
the calculation formula for each measuring disk expressed in disk units (5:
Assume that R, expressed in disk units, is known, the step cumulative values of each measuring disk expressed in disk units are: ZRI=+
!-Y
13002Rm
Can+Ma
If the sixth disk is the long rear disk, then:
ER T't(RI-bzxZ.net
According to the provisions of 18.1.1 of this regulation, take 1/2000 of the sum of the 20th step value as the dial pull, and from formula 15)
ER! = 20r! + Z4!
Only:
R! = (degree unit)
24-(disk unit)
Substitute (12) into (6)
-(1) to get the formula for the cumulative value of each measured disk step expressed in disk units,
18,2.1 Use current comparison potentiometer to calibrate the universal proportional arm bridge, no need to measure the total resistance 18.2.2 Use decimal substitution method to calibrate the universal proportional power bridge, need to measure the total resistance change. () The total resistance change of the circuit
universal proportional bridge is mainly caused by the compensation disk resistance compensation, the measuring base disk can not affect the change of the total resistance, in order to improve the sensitivity of the total resistance change line, it should be short-circuited. Figure 4 is a method for measuring the total resistance change Circuit diagram.
(2 Measurement steps
a. Connect the circuit according to the diagram, select Ra-11JIIO, RH-1×[, R,-1×100,033 and set all the indications to 4 at.
Figure 4 Measure the total resistance change line diagram
b. Connect the bridge power supply, adjust R. (the sensitivity of the ammeter is not less than 1-\/eight mm), record the indication of the ruler. Measure the resistance of each small value one by one, find out the indication of each maximum and minimum current, and mark the minimum value.
When the maximum current appears on each measuring plate, adjust R. Make the bridge almost balanced, record the balanced indication, which is the maximum value. d. When the minimum current appears on each measuring plate, please mark R. The balance indication is the difference between the maximum resistance and the minimum resistance of the smallest resistor, which is the maximum change in total resistance. 1.The total resistance variation will cause a difference in the proportional correction ratio. The most likely error is expressed by the ratio of the total resistance variation to the total error.
19 Under the condition of ensuring the total accuracy of the calibration, no other calibration methods other than those specified in the technical regulations are allowed. In case of any conflict, the method in this regulation shall prevail.
6. Processing of calibration results and calibration cycle
20. The limit error of the linearity of the universal proportional arm electrolytic measuring plate is calculated as follows: 5.6
The sum of the maximum arithmetic error of the resistance value of each plate step is equal to the sum of the maximum arithmetic error of the resistance value of one plate step. 21. The calibration data of the linearity of the measuring plate is converted according to the 1/[0 of the relative grade index. The four-tone five-person inverse method is used in the calculation:
21. The pass and fail of the electrolytic calibration are all judged by the difference between the linearity limit error of the measuring plate after rounding and the total resistance difference of the compensation plate. Only those that meet the basic error requirements are qualified, otherwise they are unqualified. 23. The universal proportional bridge that passes the calibration is issued with a control certificate; if the calibration fails, a calibration completion notice is issued, and the reasons for failure are noted.
24 Only those who fail the test can use the proportional arm electrometer. Downgrading is allowed. When it is downgraded to level one, all technical indicators must meet the requirements of that level, and a test certificate of that level must be issued, without indicating the downgraded level. 25 For all the universal proportional arm electrometers sent for inspection (including those without the previous test certificate or after treatment), a test certificate will be issued if they pass the test, and no grade will be assigned. The stability of the certificate will not be tested during the year, so no grade will be assigned for the time being. 26 The test certificate or the test result notice should clearly indicate the accuracy, relative changes and minimum accuracy of the test. 27 The test cycle should generally not exceed one year.
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