Philips PM 6670 - Definitions and Trigger Error; Definitions of Key Terms; Trigger Error Explanation

Range: 200>js. . . 200 ms, in period, time
interval arid pulse width mode, the set
hold-off time is visible with CHECK de
pressed.
On/off indication: LED indicates when
hold-off is activated.
Monitor: The selected hold-off duration can
be made visible via the gate monitor
output
On Stand By
In "ST BY" position, power is available to
maintain an ovenized crystal oscillator
heated and to recharge the optional bat
tery pack.
Check
10 MHz internal reference connected to
logic circuitry. Self-test of most measuring
functions can be selected. By using this
mode, the COUNT function provides a
stop-watch facility
Display hold
Depressing "DISP HOLD" button sets
display time to infinite and freezes the last
measurement result A new measurement
can be initiated using reset.
In the COUNT mode, the "DISP HOLD"
control is used to start and stop manual
totalizing.
Reset
Manual via pushbutton or electrical via
input E.
General
Display
Read out: 8 digits, 7,6 mm high-efficiency
LED's. Microprocessor control of display
format, decimal point and unit indication:
Hz, kHz, MHz, GHz, ns, ps, ms and s.
Display lime: Continuously variable
80ms. . .96s plus DISP HOLD.
Gate lamp: Indicates that main-gate is
opened and measurement takes place.
ST BT: Stand-by indication with LED when
instrument is not switched ON.
REMOTE:** Indicates when control over
counter is taken by the installed BUS
interface option (lEC 625 — IEEE 488).
Low-battery:** Indication by blinking display
some 15 min. before recharging is needed.
Power requirements
In addition to the normal line voltage
supply, the PM 6671 and PM 6672 can
also be powered from an optional battery
pack or external DC voltage.
Line: 115/230V ±15%; 45. . .440Hz;<25 VA,
Internal battery unit:** PM 9693.
External DC Cource:**
Voltage: 11 8V. 28V; 4.5. 8W depending
on version and options installed.
Connector: Battery jack fitting DIN 45323.
Line interference: Below VDE 0871 (B) and
MIL STD461
Safety: According to I EC 348 and
CSA 556 B.
** not available on PM 6670.
Dimensions and weight
Width: 210 mm (8.25 in)
Height: 89 mm (3.8 in).
Depth: 280 mm (11.0 in).
Weight:
Net: approx. 2.5 kg.
Shipping- approx 3.6 kg.
Environmentai conditions
Temperature:
Rated range of use: — 5°C. . . + 50°C
Storage and transport: — 40°C. . . + 70°C,
Humidity:
Operating: 10 . 90?/, RH, no condensation.
Storage: 5 , 95%RH.
Altitude/Barometric pressure
Operating. 5000m(15000ft)-53.3kN/m7
Storage: 15000 m (50000 ft)- 15.2 kN/m^.
Vibration test: According to I EC 68 Fc.
Bump test: According to lEC 68 Eb
Handling test: According to lEC 68 Ec.
Transport test: According to NLN-L88
For TIME INTERVAL AVG: LSD
2.5 X 10"'S
Definitions
LSD displayed
Unit value of Least Significant Digit,
displayed.
For FREQUENCY, PERIOD AVERAGE,
RPM and PHASE:
2.5
LSD
X
=
measuring time
FREQ or PERIOD or RPM or 360°
10'Hz
For RATIO: LSD =
_ 2.5 X prescaling factor (P) x RATIO
measuring time x FREQ A or C
(P) = 1 Channel A, all models
(P) = 256 Channel C, PM 6672.
For SINGLE TIME INTERVAL and
PULSE WIDTH:
LSD = 100ns (for times <10s).
LSD = (for times ^i^lOs).
10®
meas. time x time int. rep. rate in Hz
All calculated LSD s shall be rounded to
nearest decade (e g 5 ns will be 10ns and
0.4 Hz will be 0.1 Hz) and cannot exceed
the 8th digit
Resolution
For multiple event measurements:
FREQUENCY. PERIOD AVERAGE, RPM
and RATIO, the resolution is the smallest
increment between two measuring results
being most often 1 LSD unit. Due to arith
metic truncation, the resolution can be
2 LSD units if:
LSD X measuring time
FREO oTp^RlOD w'^M or'RAT 10
but can then be reduced to 1 LSD unit,
by doubling the measuring time.
For single event measurements:
PULSE WIDTH and SINGLE TIME INTER
VAL, the measuring resolution is 100 ns
(one clock pulse) The counter can accu
mulate up to 10'® clock pulses, of which
only the 8 most significant digits are shown
For statistical measurements:
TIME INTERVAL AVERAGE and PHASE,
the measuring resolution is the smallest
increment between two measuring results,
with confidence level of 95%.
Trigger error
Trigger error is the absolute measurement
error due to noise on the input signal
causing a too early or too late triggering
For any waveform (FREO, PERIOD, RATIO,
RPM and PULSE WIDTH):
peak-to-peak noise voltage
signal slope (V/s)
For sinewave (FREO, PERIOD, RATIO, RPM):
1
FREO X TTx S/N ratio
Example: For S/N ratio of 100 (40 dB)
and 1 second measuring time, the trigger
. .3x10"®
error is.
For separate source TIME INTERVAL:
peak noise voltage (input A) ^
signal slope A (V/s)
peak noise voltage (input B)
signal slope B (V/s)
For PHASE:
1
FREOx27r
1
X
1
S/N ratio (input A)
S/N ratio (input B)
Note: S/N ratios calculated with peak-to-
peak signal and noise values.