Specifications – Basic accuracy
- ZX74, ZX75, ZX76: (0.01% +0.002Ω) at 20ºC ±2ºC
- ZX77, ZX83, ZX84: (0.05%+0.002Ω) at 20ºC ±2ºC
- RH: < 75% non-condensing
- Insulation Resistance: >1000MΩ at 1000V
- Shipping: Dimensions: 435 x 136 x 110mm, Weight: 4kg
The ZX74 Series of Decade Resistance Boxes are very high accuracy and stable six-dial instruments. There are 4 versions in the series with a maximum resistance of 1,111,111Ω. The ZX83 series adds another two Decade Boxes that extend the resistance range to 111,111,100Ω.
The resistive elements are non-inductively wound on high quality formers using a resistance wire of specially selected alloy. Each resistive element is heat treated and undergoes a controlled ageing process to produce the very highest stability and also a low temperature coefficient.
Switches are of the highest quality with low pressure contacts for long life and reliability. Each decade switch is manufactured using a fully enclosed construction for maintenance free operation. These decade boxes are housed in attractive robust metal cases with a retractable carrying handle.
The very popular ZX74 model has a lowest decade with steps of 1mΩ. This is particularly useful for Resistance Thermometer Simulation and resistance bridge networks. All models have an extra terminal connected to the electrostatic screen which may be required in AC. bridge applications.
The ZX90 Series of Decade Resistance Boxes comprise of 10 instruments to cover a resistance range of up to 1,111,111Ω with instruments available in 4, 5, 6 and 7 Decades. Whilst they are low cost these instruments are of high quality and feature precision low contact resistance switches.
The resistive elements are made of enamelled manganin wire which is non-inductively wound onto high quality formers.
Each resistive element is heat treated and undergoes a controlled ageing process to produce the very highest stability and to achieve low temperature coefficient.
The instruments are housed in an attractive metal case which is both robust and dust proof.