When the instrument is used with an invar rod, it has the following specifications:
- Standard Deviation for 1km Double-run Levelling: ≤0.7mm
- Image Erect
- Magnification: 38×
- Objective Aperture: 50mm
- Minimum Focus: 1.6m
- Multiplication Constant: 100
- Additive Constant: 0
- Compensating Range: 15′
- Setting Accuracy: ±0.3″
- Sensitivity of Bubble: 20′/2mm
- Leveling Time: ≤2s
- Working Temperature: -30℃ to +50℃
- IP Standard: IP55
