INSTRUCTION MANUAL
Digital Multimeter
Model 178
SPECIFICATIONS
DC VOLTAGE
R A N G E
M A X I M U M
R E A D I N G
ACCURACY (12 months)
18°-28°C
±(% rdg + digits)
M A X I M U M
ALLOWABLE INPUT
1.9999
2OV
19.999
200 v
199.99
1 2 0 0 v 1200.0
Temperature Coefficient (0°-18° and 28°-55°C):
+(0.006% + 0.2 digit)/°C
Input Resistance: 10
M
± 0 . 1%
Settling Time: 1
s e c o n d t o w i t h i n 1 d i g i t o f
f i n a l r e a d i n g .
0.04% +
1d 1200V momentary
0.04% +1Id 1 2 0 0 v
0.04% +1Id 1 2 0 0 v
0.04% +1Id 1 2 0 0 v
Normal Mode Rejection Ratio:
G r e a t e r t h a n 6 0 d B a t 50Hz and 60Hz.
Common Mode Rejection Ratio
unbalance):
G r e a t e r t h a n 1 2 0 d B a t D C , 50Hz and 60Hz.
AC VOLTAGE
R A N G E
2 v
20 v
200 v
1000 v
M A X I M U M
R E A D I N G
1.9999
19.999
199.99
1000.0
ACCURACY (12 months) TEMPERATURE COEFFICIENT
(above 2000 counts) 0 ° - I 8° and 28°-55°C
1 8 ° - 2 8 ° C ; 1 00Hz-1 Ok Hz ±(% rdg + digits)/°C
±(% rdg + digits)
45Hz-10kHz I0kHz-20kHz
0.4% +
15d 0.04% + 0.5d
0.09% + 0.5d
0.3% + 15d 0.01% + 0.5d
0.03% + 0.5d
0.3% + 15d 0.01% + 0.5d
0.03% + 0.5d
0.3% + 15d 0.01% + 0.5d
0.03% + 0.5d
Extended Frequency Accuracy: Input Impedance:
(45Hz-100Hz) ±(0.5% + 1 5 d i g i t s )
+ 1 % s h u n t e d b y l e s s t h a n 7 5 p F .
(10kHz-20kHz) ±(1.0% + 1 5 d i g i t s )
Maximum Allowable Input Voltage:
Response:
A v e r a g e r e s p o n d i n g c a l i b r a t e d i n r m s 1 0 0 0 V r m s , 1 4 0 0 V p e a k , 10
7
V·Hz m a x i m u m .
o f a s i n e w a v e .
Common Mode Rejection Ratio
unbalance):
Settling Time:
2 . 5 s e c o n d s t o w i t h i n 1 0 d i g i t s 6 0 d B a t D C , 50Hz a n d 60Hz.
o f f i n a l r e a d i n g .
RESISTANCE
A C C U R A C Y ( 1 2 m o n t h s ) T E M P E R A T U R E C O E F F I C I E N T
M A X I M U M 1 8 ° - 2 8 ° C 0 ° - 1 8 ° and 2 8 ° - 5 5 ° C
N O M I N A L
R A N G E R E A D I N G ±(% rdg + digits)
±(% rdg + digits)/°C
APPLIED CURRENT
1.9999
0.04% +
2d 0.003% + 0.2d 1mA
20
19.999 0.04% +
I d 0.003% + 0.2d
200
A
199.99 0.04% + I d 0.003% + 0.2d
A
2000
1999.9 0.04% + I d 0.003% + 0.2d
A
19.999 0.10% + 1 d 0.02 % + 0.2d
A
M a x i m u m A l l o w a b l e I n p u t :
2 5 0 V r m s s i n e , 3 5 0 V p e a k .
Maximum Voltage
Across Unknown: 2V
within range,
5 V o p e n c i r c u i t .
GENERAL
D I S P L A Y :
F i v e 0 . 5 ” L E D d i g i t s , a p p r o p r i a t e
d e c i m a l p o s i t i o n a n d p o l a r i t y i n d i c a t i o n .
CONVERSION PERIOD: 400
milliseconds.
ENVIRONMENT:
Operating:
0 ° C to 5 5 ° C ;
0 % t o 8 0 % r e l a t i v e h u m i d i t y u p t o 40°C.
Storage:
- 2 5 ° C t o + 6 5 ° C .
Settling Time:
1 s e c o n d t o w i t h i n 1 d i g i t o f f i n a l
r e a d i n g e x c e p t 2 s e c o n d s o n t h e
range.
POWER:
1 0 5 - 1 2 5 o r 2 1 0 - 2 5 0 v o l t s ( s w i t c h s e l e c -
t e d ) , 9 0 - I 10V a v a i l a b l e . 50-60Hz, 7 watts.
O p t i o n a l 6 h o u r b a t t e r y p a c k , M o d e l 1 7 8 8 .
DIMENSIONS, WEIGHT:
85mm high x 235mm
w i d e x 2 7 5 m m d e e p (3-1/2 in. x 9-1/4 in. x
10-3/4 i n . ) . N e t w e i g h t : 1.7kg (3lbs., 13 oz).
OVERRANGE INDICATION:
Display blinks all
z e r o s a b o v e 1 9 9 9 9 c o u n t s .
MAXIMUM COMMON MODE VOLTAGE:
1400V peak.
AA