Guarded High Resistance Standards

LEADING MANUFACTURER – OVER 500 STANDARDS BUILT & DELIVERED
RESISTANCE FROM 1 MΩ TO 10 TΩ
NEW: IMPROVED TCR & VCR
TYPE N, TRIAX or BNC CONNECTORS
HIGH IMMUNITY FROM ENVIRONMENTAL EFFECTS
FULLY GUARDED – FOR ANY RATIO ON ANY MEASUREMENT SYSTEM

Ohm-Labs is the leader in guarded high resistance standards, the first to manufacture this design commercially, and the most experienced, with hundreds of guarded high resistance standards delivered to labs around the world.

The 100-series guarded high resistance standards are designed for laboratory or on-site calibration use. Their low coefficients of temperature allow them to be used in a variety of environments without loss of accuracy. Hermetically sealed construction provides immunity from changes in barometric pressure and relative humidity. They are not affected by moderate vibration or shock. Low reactance allows their use as DC or AC standards. All models are housed in a rugged, die-cast aluminum case.

Connection is via type N sockets. The shields are for a guard circuit driven at measurement potential. Either terminal may be high. Triax and BNC connectors are available as options.

The guards are internally connected by a high value resistor nominally equal to the standard. This provides balanced guard voltages for any type of measurement system at any ratio.

A 5-way insulated binding post for banana plugs or spade lugs is provided for grounding the case.

A 10 K (nominal, at 25 °C) thermistor is included to monitor the internal temperature of the standard. Connection is via standard 2 mm mini banana plugs.

Decade resistance values are standard; other values are available on request.

All models include ISO 17025 accredited calibration at two voltages and temperature coefficient determination.

A lower accuracy -AF type is available in compliance with Air Force specifications.

Model Number	Nominal Resistance	Initial Tolerance in ppm	Temperature Coefficient (less than)	Voltage Coefficient (less than}	6 month Stability	12 month Stability	Recom. Voltage

106-H	1 Meg	5	1 ppm / °C	0.1 ppm / V	<3 ppm	<5 ppm	10
107-H	10 Meg	10	10	0.1	5	10	20
108	100 Meg	20	20	0.1	10	20	50
109	1 Gig	35	30	0.1	15	25	100
110	10 Gig	50	35	0.1	25	50	100
111	100 Gig	200	50	0.2	50	100	200
112	1 Tera	500	50	1	100	200	500
113	10 Tera	1000	500	2	150	300	500

Notes

Tolerance is at time of manufacture.
Temperature coefficient is at nominal 23 °C +/-5°C.
Voltage coefficient is at recommended –50 % / +100 %
Max V: 106 1 kV, 107 3 kV, 108-110 10 kV, 111-113: 15 kV
10 teraohm and above models are pending product redesign

Physical

22 x 13 x 13 cm / 8.5 x 5 x 5 in; 2.5 kg / 5 lbs

Optional Accessories

Thermistor cable: 2 meters, standard 4mm dual banana to mini dual banana
Transit Cases for 1, 2 or 4 standards
Low noise for High Resistance – Specify connectors