Pendulum CNT-90 - Measurement Uncertainties

Specifications
Timebase Options
Product Family
'9X'
Option
Timebase Type
Standard
UCXO
Option 19/90
OCXO
Option 30/90
OCXO
Option 40/90
OCXO
Uncertainty due to:
-Calibration adjustment tolerance @ +23
°C ± 3°C
<1x10
-6
<5x10
-8
<1x10
-8
<3x10
-9
-Aging
per 24 h
per month
per year
1)
7
<5x10
-
<5x10
-6
92)
<5x10
-
<6x10
-8
<2x10
-7
2)
<5x10
-10
8
<1x10
-
<5x10
-8
2)
<3x10
-10
<3x10
-9
<1.5x10
-8
-Temperature variation:
0 °C - 50 °C
20 °C - 26 °C (typ. values)
5
<1x10
-
<3x10
-6
<5x10
-8
<2x10
-8
<5x10
-9
<1x10
-9
<2.5x10
-9
<4x10
-10
-Power voltage variation: ±10%
<1x10
-8
<5x10
-9
<5x10
-10
<5x10
-10
Short term stability:
(Root Allan Variance)
 = 1 s
Typical values  = 1 0 s
not specified
10
<1x10
-
10
<1x10
-
1x10
-11
1x10
-11
5x10
-12
5x10
-12
Power-on stability:
-Deviation versus final value after 24 h
on time, after a warm-up time of:
1)
30 min
<1x10
-7
30 min
<1x10
-8
10 min
<5x10
-9
10 min
Total uncertainty, for operating
temperature 0°C to 50 °C, @ 2  (95 %)
confidence interval:
-1 year after calibration
-2 years after calibration
<1.2x10
-5
<1.5x10
-5
2.4x10
-7
4.6x10
-7
8
<6x10
-
<1.2x10
-7
<1.8x10
-8
<3.6x10
-8
Typical total uncertainty, for operating
temperature 20°C to 26 °C, @ 2  (95 %)
confidence interval:
-1 year after calibration
-2 years after calibration
6
<7x10
-
<1.2x10
-5
<2.4x10
-7
<4.6x10
-7
8
<6x10
-
<1.2x10
-7
<1.7x10
-8
<3.5x10
-8
Explanations
1)
Negligible in comparison with the deviation caused by 1 °C temperature change.
2)
After 1 month of continuous operation.
NOTE: Electrical adjustment by means of tuning voltage from DAC; no potentiometer trimming.
Serial interface to all optional oscillators for closed-case calibration and status reporting.
UCXO: Uncompensated Crystal Oscillator
OCXO: Oven Controlled Crystal Oscillator
8-15
USER MANUAL ● CNT 9x Series ● Rev.22 February 2020