Table 2.

Overview of rotational seismometers using direct measurement (only the most important parameters are listed).

Parameter	Unit	HZ1-200-100 [67]	R-1 [68]	R-2 [69]
Axial		uniaxial	triaxial	triaxial
Sensitivity (1)	rad/s/√Hz	4.4 × 10−4	1.2 × 10−7	0.6 × 10−7
Clip level (2)	rad/s	3.49	0.10	0.40
Dynamic range	dB	78	110	117
Frequency band	Hz	>60	0.05–20	0.03–50
optional extended		n/a	0.03–50	0.01–100
Scale factor (3)	V/rad/s	0.57(±2%)	50	50
optional		n/a	2 × 102	5–2 × 102
Operating temperature	°C	−40 to +71	−15 to +55 (extended −45 to +55)
Output signal	V	+0.5 to +4.5	±5, ±2.5	±20 differential
Calibration (S.F. deviation from 20/22 °C)	%/°C	<0.08	<0.03	Internal calibration electronics
Shock survival	g	200	200	200
Power supply	VDC	8–12	9–14	9–18
Supply current	mA	<20	20	30
Power consumption	W	0.24	0.28	0.54
Weight	kg	<0.06	1.0	1.5
Dimensions [L × W × H]	mm	58.3 × 25.3 × 25.3	120 × 120 × 90	120 × 120 × 100
NEMA rating		4	4	Waterproof (submersible)
Software	type	Own	Own	Own

⁽¹⁾ For unambiguous comparison with data in Table 1, this is output noise for SNR = 1, also defined as resolution @ 1 Hz in [rad/s]; ⁽²⁾ Identical to the maximum rate in Table 1; ⁽³⁾ Understood as the gain of the instrument ([7], p. 79).