The back contains 5 scales of the following types:
| Type (click to view scale details) |
Range & Units | Numbered | Geometry | Location |
|---|---|---|---|---|
| Altitude | 0 - 90, Degrees | Every 5 degrees | Circular, concentric | Upper right quadrant of outer circular on back of instrument. |
| Altitude | 0 - 90, Degrees | Every 5 degrees | Circular, concentric | Upper left quadrant of outer circular on back of instrument. |
| Dastūr Circle | None | Not numbered | Angle | Upper left quadrant (inside circular scales) |
| Zodiacal signs | Aries - Pisces, Zodiacal sign | Not numbered | Circular, concentric | Circular scale immediately inside the outer scale - refers to the full circle |
| Terms | 0° Aries - 30° Pisces, Zodiacal divisions, equal or unequal | At each term | Circular, concentric | Circular scale second in from the outer scale - refers to the full circle. |
| Faces | 0° Aries - 30° Pisces, Zodiacal divisions, equal or unequal | Not numbered | Circular, concentric | Circular scale third in from the outer scale - refers to the full circle. |
| Transcription | Translation | Notes | Type |
|---|---|---|---|
| بسم الله وبعون الله باليمن والدولة وباﻹقبال والسعادة ألف هذا الأصطرلاب أحمد ومحمد أبناء ٳبراهيم الأصطرلابي الأصفهاني سنة أربع وتسعين وثلثمائةة | In the name of God, and by the help of God. With prosperity and success and good fortune and happiness, this astrolabe was composed by Aḥmad and Muḥammad, sons of Ibrāhīm, maker of astrolabes from Isfahan, the year 394. | Inscription across middle of back | Maker's signature |
| [vertically on the back] | [ pending ] | None |