b.
Specifications.
are not necessarily verified in this procedure.
1
Input requirements .... 105-125 volts a-c, 60 cps single
a.
Calibration
4. General Instructions.
phase.
Reporting.
During the performance of this procedure,
Accuracy...................... 3% full scale from 10 mv up 4% on
annotate DA Form 2407 (Maintenance Request) in
lower ranges.
accordance with TM 38-750.
Sensitivity..................... 1 mv d-c, mid-zero.
b. Frequency of Calibration. The maximum time
Total ranges ................ 13 ranges, 1 mv and 2.5 mv mid-
permitted between calibration checks for Mlillivoltmeter
zero, 10 mv to 1,000 volts left-
ME-227/U is contained in TB 11-6625-692-15/1.
zero.
c. Reporting
Requirements.
Report
1
Input impedance ......... 1 mv to 100 mv, 6 megohms 250
accomplishment of maintenance level calibration only
mv 16 megohms volt to 1,000
when required as instructed in TB 11-6625-692-15/1.
volts, left-zero.
d. Unit Under Test. Millivoltmeter NME-227/U will
1
Zero drift ..................... Less than 1% from 10 mv up, 3%
be referred to as "unit under test."
on lower ranges.
e. Removal. Do not remove the unit under test
from its protective case unless necessitated by equipment
c.
Program Data.
connections and/or components to be adjusted which are
not accessible from external ports provided on the unit
Time required for calibra- .... 2 hours (approx.).
under test.
tion.
Calibration level ................... Maintenance.
5.
Differences Among Models. None.
1
These specifications are for information only and
SECTION II
CALIBRATION
calibration.
6. Equipment Required. Equipment required for
calibration performance checks and adjustments is listed
7. Preliminary Procedure. a. Remove rear cover
from unit under test.
not available, equivalent calibrated item may be used.
b. Adjust meter zero adjustment screw if required.
Table 1. Equipment Required for Calibration Performance
c. Connect equipment to 115 vac bench power;
Checks and Adjustments
energize, and allow 15 minutes for warmup and
A. Authorized Calibration Equipment
stabilization.
Warning: Because of wiring, rear cover of unit
Nomenclature
Federal stock
under test cannot be removed completely. Therefore,
No.
use CAUTION when making adjustments to prevent
1
DECADE RESISTOR ZM-16/U
6625-669-0266
contact with fuse holder which is at 115 vac potential.
ELECTRONIC VOLTMETER ME-
202/U
6625-709-0288
Note. The following paragraphs are divided into
METER TEST SET TS-682/GSM-1
6625-669-0747
subparagraph a, performance check, and subparagraph b,
1
Two required.
adjustments. When the performance check is within
tolerance, do not perform the corresponding adjustment.
B. Authorized Accessories
When the performance check is not within tolerance,
Nomenclature
Federal stock
Description
perform the corresponding adjustment before continuing
with the calibration procedure. When the performance
No.
check is not within tolerance and no adjustment is
1
ADAPTER
4931-739-
Single banana
specified, the deficiency must be corrected before
4416
jack to spade
continuing with the procedure.
lug.
2
ELECTRICAL LEAD
4931-739-
24-inch single
8. Mid-zero Ranges. a. Performance Check.
4432
banana jack
(1) Connect equipment as shown in figure 2.
terminations.
(2) Position controls on unit under test as listed in (a)
1
Four required.
through (c) below.
2
Two required.
(a)
LOW MVS switch to 1 MV MID-ZERO.
Note. It is recommended that personnel familiarize
themselves with the entire procedure prior to performing
3
